diff --git a/java/res/values/attrs.xml b/java/res/values/attrs.xml
index 5c62003..769a1d9 100644
--- a/java/res/values/attrs.xml
+++ b/java/res/values/attrs.xml
@@ -74,6 +74,7 @@
         <!-- Size of the text for spacebar language label, in the proportion of key height. -->
         <attr name="languageOnSpacebarTextRatio" format="fraction" />
         <attr name="languageOnSpacebarTextColor" format="color" />
+        <attr name="languageOnSpacebarTextShadowRadius" format="float" />
         <attr name="languageOnSpacebarTextShadowColor" format="color" />
         <!-- Background image for the spacebar. -->
         <attr name="spacebarBackground" format="reference" />
diff --git a/java/res/values/colors.xml b/java/res/values/colors.xml
index dabb4d6..baa0887 100644
--- a/java/res/values/colors.xml
+++ b/java/res/values/colors.xml
@@ -26,7 +26,6 @@
     <color name="suggested_word_color_ics">#B233B5E5</color>
     <color name="highlight_translucent_color_ics">#9933B5E5</color>
     <color name="key_text_color_holo">@android:color/white</color>
-    <color name="key_text_shadow_color_holo">@android:color/transparent</color>
     <color name="key_text_inactivated_color_holo">#66E0E4E5</color>
     <color name="key_hint_letter_color_holo">#80000000</color>
     <color name="key_hint_label_color_holo">#A0FFFFFF</color>
diff --git a/java/res/values/strings-talkback-descriptions.xml b/java/res/values/strings-talkback-descriptions.xml
index 4ffca10..80406d0 100644
--- a/java/res/values/strings-talkback-descriptions.xml
+++ b/java/res/values/strings-talkback-descriptions.xml
@@ -35,10 +35,14 @@
     <string name="spoken_description_unknown">Key code %d</string>
     <!-- Spoken description for the "Shift" keyboard key when "Shift" is off. -->
     <string name="spoken_description_shift">Shift</string>
+    <!-- Spoken description for the "Shift" keyboard key in symbols mode. -->
+    <string name="spoken_description_symbols_shift">More symbols</string>
     <!-- Spoken description for the "Shift" keyboard key when "Shift" is on. -->
-    <string name="spoken_description_shift_shifted">Shift on (tap to disable)</string>
+    <string name="spoken_description_shift_shifted">Shift</string>
+    <!-- Spoken description for the "Shift" keyboard key in 2nd symbols (a.k.a. symbols shift) mode. -->
+    <string name="spoken_description_symbols_shift_shifted">Symbols</string>
     <!-- Spoken description for the "Shift" keyboard key when "Caps lock" is on. -->
-    <string name="spoken_description_caps_lock">Caps lock on (tap to disable)</string>
+    <string name="spoken_description_caps_lock">Shift</string>
     <!-- Spoken description for the "Delete" keyboard key. -->
     <string name="spoken_description_delete">Delete</string>
     <!-- Spoken description for the "To Symbol" keyboard key. -->
@@ -76,8 +80,8 @@
     <string name="spoken_description_shiftmode_locked">Caps lock enabled</string>
     <!-- Spoken feedback after changing to the symbols keyboard. -->
     <string name="spoken_description_mode_symbol">Symbols mode</string>
-    <!-- Spoken feedback after changing to the symbols shift keyboard. -->
-    <string name="spoken_description_mode_symbol_shift">Symbols shift mode</string>
+    <!-- Spoken feedback after changing to the 2nd symbols (a.k.a. symbols shift) keyboard. -->
+    <string name="spoken_description_mode_symbol_shift">More symbols mode</string>
     <!-- Spoken feedback after changing to the alphanumeric keyboard. -->
     <string name="spoken_description_mode_alpha">Letters mode</string>
     <!-- Spoken feedback after changing to the phone dialer keyboard. -->
diff --git a/java/res/values/themes-ics.xml b/java/res/values/themes-ics.xml
index 616dbd8..d7943ee 100644
--- a/java/res/values/themes-ics.xml
+++ b/java/res/values/themes-ics.xml
@@ -56,8 +56,8 @@
         <item name="keyShiftedLetterHintInactivatedColor">@color/key_shifted_letter_hint_inactivated_color_holo</item>
         <item name="keyShiftedLetterHintActivatedColor">@color/key_shifted_letter_hint_activated_color_holo</item>
         <item name="keyPreviewTextColor">@color/key_text_color_holo</item>
-        <item name="keyTextShadowColor">@color/key_text_shadow_color_holo</item>
-        <item name="keyTextShadowRadius">0.0</item>
+        <!-- A negative value to disable key text shadow layer. -->
+        <item name="keyTextShadowRadius">-1.0</item>
     </style>
     <style
         name="MainKeyboardView.ICS"
@@ -71,6 +71,7 @@
         <item name="autoCorrectionSpacebarLedEnabled">false</item>
         <item name="autoCorrectionSpacebarLedIcon">@drawable/sym_keyboard_space_led_holo</item>
         <item name="languageOnSpacebarTextColor">@color/spacebar_text_color_holo</item>
+        <item name="languageOnSpacebarTextShadowRadius">1.0</item>
         <item name="languageOnSpacebarTextShadowColor">@color/spacebar_text_shadow_color_holo</item>
         <item name="spacebarBackground">@drawable/btn_keyboard_spacebar_ics</item>
     </style>
diff --git a/java/res/values/themes-klp.xml b/java/res/values/themes-klp.xml
index 9bb3d79..13500fe 100644
--- a/java/res/values/themes-klp.xml
+++ b/java/res/values/themes-klp.xml
@@ -56,8 +56,8 @@
         <item name="keyShiftedLetterHintInactivatedColor">@color/key_shifted_letter_hint_inactivated_color_holo</item>
         <item name="keyShiftedLetterHintActivatedColor">@color/key_shifted_letter_hint_activated_color_holo</item>
         <item name="keyPreviewTextColor">@color/key_text_color_holo</item>
-        <item name="keyTextShadowColor">@color/key_text_shadow_color_holo</item>
-        <item name="keyTextShadowRadius">0.0</item>
+        <!-- A negative value to disable key text shadow layer. -->
+        <item name="keyTextShadowRadius">-1.0</item>
     </style>
     <style
         name="MainKeyboardView.KLP"
@@ -71,6 +71,7 @@
         <item name="autoCorrectionSpacebarLedEnabled">false</item>
         <item name="autoCorrectionSpacebarLedIcon">@drawable/sym_keyboard_space_led_holo</item>
         <item name="languageOnSpacebarTextColor">@color/spacebar_text_color_holo</item>
+        <item name="languageOnSpacebarTextShadowRadius">1.0</item>
         <item name="languageOnSpacebarTextShadowColor">@color/spacebar_text_shadow_color_holo</item>
         <item name="spacebarBackground">@drawable/btn_keyboard_spacebar_klp</item>
     </style>
diff --git a/java/res/values/themes-lmp.xml b/java/res/values/themes-lmp.xml
index 773da19..41c4d09 100644
--- a/java/res/values/themes-lmp.xml
+++ b/java/res/values/themes-lmp.xml
@@ -56,8 +56,8 @@
         <item name="keyShiftedLetterHintInactivatedColor">@color/key_shifted_letter_hint_inactivated_color_holo</item>
         <item name="keyShiftedLetterHintActivatedColor">@color/key_shifted_letter_hint_activated_color_holo</item>
         <item name="keyPreviewTextColor">@color/key_text_color_holo</item>
-        <item name="keyTextShadowColor">@color/key_text_shadow_color_holo</item>
-        <item name="keyTextShadowRadius">0.0</item>
+        <!-- A negative value to disable key text shadow layer. -->
+        <item name="keyTextShadowRadius">-1.0</item>
     </style>
     <style
         name="MainKeyboardView.LMP"
@@ -71,6 +71,7 @@
         <item name="autoCorrectionSpacebarLedEnabled">false</item>
         <item name="autoCorrectionSpacebarLedIcon">@drawable/sym_keyboard_space_led_holo</item>
         <item name="languageOnSpacebarTextColor">@color/spacebar_text_color_holo</item>
+        <item name="languageOnSpacebarTextShadowRadius">1.0</item>
         <item name="languageOnSpacebarTextShadowColor">@color/spacebar_text_shadow_color_holo</item>
         <item name="spacebarBackground">@drawable/btn_keyboard_spacebar_lmp</item>
     </style>
diff --git a/java/src/com/android/inputmethod/accessibility/KeyCodeDescriptionMapper.java b/java/src/com/android/inputmethod/accessibility/KeyCodeDescriptionMapper.java
index 2e6649b..0499a34 100644
--- a/java/src/com/android/inputmethod/accessibility/KeyCodeDescriptionMapper.java
+++ b/java/src/com/android/inputmethod/accessibility/KeyCodeDescriptionMapper.java
@@ -189,9 +189,14 @@
             break;
         case KeyboardId.ELEMENT_ALPHABET_AUTOMATIC_SHIFTED:
         case KeyboardId.ELEMENT_ALPHABET_MANUAL_SHIFTED:
-        case KeyboardId.ELEMENT_SYMBOLS_SHIFTED:
             resId = R.string.spoken_description_shift_shifted;
             break;
+        case KeyboardId.ELEMENT_SYMBOLS:
+            resId = R.string.spoken_description_symbols_shift;
+            break;
+        case KeyboardId.ELEMENT_SYMBOLS_SHIFTED:
+            resId = R.string.spoken_description_symbols_shift_shifted;
+            break;
         default:
             resId = R.string.spoken_description_shift;
         }
diff --git a/java/src/com/android/inputmethod/keyboard/KeyboardView.java b/java/src/com/android/inputmethod/keyboard/KeyboardView.java
index 8ca00b0..4450a44 100644
--- a/java/src/com/android/inputmethod/keyboard/KeyboardView.java
+++ b/java/src/com/android/inputmethod/keyboard/KeyboardView.java
@@ -82,6 +82,7 @@
     private final float mVerticalCorrection;
     private final Drawable mKeyBackground;
     private final Rect mKeyBackgroundPadding = new Rect();
+    private static final float KET_TEXT_SHADOW_RADIUS_DISABLED = -1.0f;
 
     // HORIZONTAL ELLIPSIS "...", character for popup hint.
     private static final String POPUP_HINT_CHAR = "\u2026";
@@ -133,7 +134,7 @@
         mKeyShiftedLetterHintPadding = keyboardViewAttr.getDimension(
                 R.styleable.KeyboardView_keyShiftedLetterHintPadding, 0.0f);
         mKeyTextShadowRadius = keyboardViewAttr.getFloat(
-                R.styleable.KeyboardView_keyTextShadowRadius, 0.0f);
+                R.styleable.KeyboardView_keyTextShadowRadius, KET_TEXT_SHADOW_RADIUS_DISABLED);
         mVerticalCorrection = keyboardViewAttr.getDimension(
                 R.styleable.KeyboardView_verticalCorrection, 0.0f);
         keyboardViewAttr.recycle();
@@ -414,18 +415,23 @@
                 }
             }
 
-            paint.setColor(key.selectTextColor(params));
             if (key.isEnabled()) {
-                // Set a drop shadow for the text
-                paint.setShadowLayer(mKeyTextShadowRadius, 0.0f, 0.0f, params.mTextShadowColor);
+                paint.setColor(key.selectTextColor(params));
+                // Set a drop shadow for the text if the shadow radius is positive value.
+                if (mKeyTextShadowRadius > 0.0f) {
+                    paint.setShadowLayer(mKeyTextShadowRadius, 0.0f, 0.0f, params.mTextShadowColor);
+                } else {
+                    paint.clearShadowLayer();
+                }
             } else {
                 // Make label invisible
                 paint.setColor(Color.TRANSPARENT);
+                paint.clearShadowLayer();
             }
             blendAlpha(paint, params.mAnimAlpha);
             canvas.drawText(label, 0, label.length(), positionX, baseline, paint);
             // Turn off drop shadow and reset x-scale.
-            paint.setShadowLayer(0.0f, 0.0f, 0.0f, Color.TRANSPARENT);
+            paint.clearShadowLayer();
             paint.setTextScaleX(1.0f);
 
             if (icon != null) {
diff --git a/java/src/com/android/inputmethod/keyboard/MainKeyboardView.java b/java/src/com/android/inputmethod/keyboard/MainKeyboardView.java
index 8f79a91..1a8e4b7 100644
--- a/java/src/com/android/inputmethod/keyboard/MainKeyboardView.java
+++ b/java/src/com/android/inputmethod/keyboard/MainKeyboardView.java
@@ -74,6 +74,7 @@
  * @attr ref R.styleable#MainKeyboardView_autoCorrectionSpacebarLedIcon
  * @attr ref R.styleable#MainKeyboardView_languageOnSpacebarTextRatio
  * @attr ref R.styleable#MainKeyboardView_languageOnSpacebarTextColor
+ * @attr ref R.styleable#MainKeyboardView_languageOnSpacebarTextShadowRadius
  * @attr ref R.styleable#MainKeyboardView_languageOnSpacebarTextShadowColor
  * @attr ref R.styleable#MainKeyboardView_spacebarBackground
  * @attr ref R.styleable#MainKeyboardView_languageOnSpacebarFinalAlpha
@@ -129,7 +130,9 @@
     private final float mLanguageOnSpacebarTextRatio;
     private float mLanguageOnSpacebarTextSize;
     private final int mLanguageOnSpacebarTextColor;
+    private final float mLanguageOnSpacebarTextShadowRadius;
     private final int mLanguageOnSpacebarTextShadowColor;
+    private static final float LANGUAGE_ON_SPACEBAR_TEXT_SHADOW_RADIUS_DISABLED = -1.0f;
     // The minimum x-scale to fit the language name on spacebar.
     private static final float MINIMUM_XSCALE_OF_LANGUAGE_NAME = 0.8f;
     // Stuff to draw auto correction LED on spacebar.
@@ -231,6 +234,9 @@
                 R.styleable.MainKeyboardView_languageOnSpacebarTextRatio, 1, 1, 1.0f);
         mLanguageOnSpacebarTextColor = mainKeyboardViewAttr.getColor(
                 R.styleable.MainKeyboardView_languageOnSpacebarTextColor, 0);
+        mLanguageOnSpacebarTextShadowRadius = mainKeyboardViewAttr.getFloat(
+                R.styleable.MainKeyboardView_languageOnSpacebarTextShadowRadius,
+                LANGUAGE_ON_SPACEBAR_TEXT_SHADOW_RADIUS_DISABLED);
         mLanguageOnSpacebarTextShadowColor = mainKeyboardViewAttr.getColor(
                 R.styleable.MainKeyboardView_languageOnSpacebarTextShadowColor, 0);
         mLanguageOnSpacebarFinalAlpha = mainKeyboardViewAttr.getInt(
@@ -948,12 +954,17 @@
             final float descent = paint.descent();
             final float textHeight = -paint.ascent() + descent;
             final float baseline = height / 2 + textHeight / 2;
-            paint.setColor(mLanguageOnSpacebarTextShadowColor);
-            paint.setAlpha(mLanguageOnSpacebarAnimAlpha);
-            canvas.drawText(language, width / 2, baseline - descent - 1, paint);
+            if (mLanguageOnSpacebarTextShadowRadius > 0.0f) {
+                paint.setShadowLayer(mLanguageOnSpacebarTextShadowRadius, 0, 0,
+                        mLanguageOnSpacebarTextShadowColor);
+            } else {
+                paint.clearShadowLayer();
+            }
             paint.setColor(mLanguageOnSpacebarTextColor);
             paint.setAlpha(mLanguageOnSpacebarAnimAlpha);
             canvas.drawText(language, width / 2, baseline - descent, paint);
+            paint.clearShadowLayer();
+            paint.setTextScaleX(1.0f);
         }
 
         // Draw the spacebar icon at the bottom
diff --git a/java/src/com/android/inputmethod/latin/BinaryDictionary.java b/java/src/com/android/inputmethod/latin/BinaryDictionary.java
index 94a1e36..999508e 100644
--- a/java/src/com/android/inputmethod/latin/BinaryDictionary.java
+++ b/java/src/com/android/inputmethod/latin/BinaryDictionary.java
@@ -414,8 +414,8 @@
         public WordProperty mWordProperty;
         public int mNextToken;
 
-        public GetNextWordPropertyResult(final WordProperty wordPreperty, final int nextToken) {
-            mWordProperty = wordPreperty;
+        public GetNextWordPropertyResult(final WordProperty wordProperty, final int nextToken) {
+            mWordProperty = wordProperty;
             mNextToken = nextToken;
         }
     }
diff --git a/native/jni/NativeFileList.mk b/native/jni/NativeFileList.mk
index 34c1907..6ccfec9 100644
--- a/native/jni/NativeFileList.mk
+++ b/native/jni/NativeFileList.mk
@@ -46,23 +46,22 @@
     $(addprefix suggest/policyimpl/dictionary/, \
         header/header_policy.cpp \
         header/header_read_write_utils.cpp \
-        shortcut/shortcut_list_reading_utils.cpp \
         structure/dictionary_structure_with_buffer_policy_factory.cpp) \
-    $(addprefix suggest/policyimpl/dictionary/bigram/, \
-        bigram_list_read_write_utils.cpp \
-        ver4_bigram_list_policy.cpp) \
     $(addprefix suggest/policyimpl/dictionary/structure/pt_common/, \
+        bigram/bigram_list_read_write_utils.cpp \
         dynamic_pt_gc_event_listeners.cpp \
         dynamic_pt_reading_helper.cpp \
         dynamic_pt_reading_utils.cpp \
         dynamic_pt_updating_helper.cpp \
         dynamic_pt_writing_utils.cpp \
-        patricia_trie_reading_utils.cpp) \
+        patricia_trie_reading_utils.cpp \
+        shortcut/shortcut_list_reading_utils.cpp ) \
     $(addprefix suggest/policyimpl/dictionary/structure/v2/, \
         patricia_trie_policy.cpp \
         ver2_patricia_trie_node_reader.cpp \
         ver2_pt_node_array_reader.cpp) \
     $(addprefix suggest/policyimpl/dictionary/structure/v4/, \
+        bigram/ver4_bigram_list_policy.cpp \
         ver4_dict_buffers.cpp \
         ver4_dict_constants.cpp \
         ver4_patricia_trie_node_reader.cpp \
diff --git a/native/jni/com_android_inputmethod_latin_BinaryDictionary.cpp b/native/jni/com_android_inputmethod_latin_BinaryDictionary.cpp
index a3d8ec1..a55b2da 100644
--- a/native/jni/com_android_inputmethod_latin_BinaryDictionary.cpp
+++ b/native/jni/com_android_inputmethod_latin_BinaryDictionary.cpp
@@ -335,7 +335,7 @@
     if (!shortcutTargetCodePoints.empty()) {
         shortcuts.emplace_back(&shortcutTargetCodePoints, shortcutProbability);
     }
-    // Use 1 for count to indicate the word has inputed.
+    // Use 1 for count to indicate the word has inputted.
     const UnigramProperty unigramProperty(isNotAWord, isBlacklisted,
             probability, timestamp, 0 /* level */, 1 /* count */, &shortcuts);
     dictionary->addUnigramWord(codePoints, codePointCount, &unigramProperty);
@@ -353,8 +353,12 @@
     jsize word1Length = env->GetArrayLength(word1);
     int word1CodePoints[word1Length];
     env->GetIntArrayRegion(word1, 0, word1Length, word1CodePoints);
-    dictionary->addBigramWords(word0CodePoints, word0Length, word1CodePoints,
-            word1Length, probability, timestamp);
+    const std::vector<int> bigramTargetCodePoints(
+            word1CodePoints, word1CodePoints + word1Length);
+    // Use 1 for count to indicate the bigram has inputted.
+    const BigramProperty bigramProperty(&bigramTargetCodePoints, probability,
+            timestamp, 0 /* level */, 1 /* count */);
+    dictionary->addBigramWords(word0CodePoints, word0Length, &bigramProperty);
 }
 
 static void latinime_BinaryDictionary_removeBigramWords(JNIEnv *env, jclass clazz, jlong dict,
@@ -437,14 +441,18 @@
                     env->GetIntField(languageModelParam, shortcutProbabilityFieldId);
             shortcuts.emplace_back(&shortcutTargetCodePoints, shortcutProbability);
         }
-        // Use 1 for count to indicate the word has inputed.
+        // Use 1 for count to indicate the word has inputted.
         const UnigramProperty unigramProperty(isNotAWord, isBlacklisted,
                 unigramProbability, timestamp, 0 /* level */, 1 /* count */, &shortcuts);
         dictionary->addUnigramWord(word1CodePoints, word1Length, &unigramProperty);
         if (word0) {
             jint bigramProbability = env->GetIntField(languageModelParam, bigramProbabilityFieldId);
-            dictionary->addBigramWords(word0CodePoints, word0Length, word1CodePoints, word1Length,
-                    bigramProbability, timestamp);
+            const std::vector<int> bigramTargetCodePoints(
+                    word1CodePoints, word1CodePoints + word1Length);
+            // Use 1 for count to indicate the bigram has inputted.
+            const BigramProperty bigramProperty(&bigramTargetCodePoints, bigramProbability,
+                    timestamp, 0 /* level */, 1 /* count */);
+            dictionary->addBigramWords(word0CodePoints, word0Length, &bigramProperty);
         }
         if (dictionary->needsToRunGC(true /* mindsBlockByGC */)) {
             return i + 1;
@@ -558,11 +566,9 @@
                 return false;
             }
         }
-        for (const BigramProperty &bigarmProperty : *wordProperty.getBigramProperties()) {
-            const std::vector<int> *targetCodePoints = bigarmProperty.getTargetCodePoints();
+        for (const BigramProperty &bigramProperty : *wordProperty.getBigramProperties()) {
             if (!dictionaryStructureWithBufferPolicy->addBigramWords(wordCodePoints, wordLength,
-                    targetCodePoints->data(), targetCodePoints->size(),
-                    bigarmProperty.getProbability(), bigarmProperty.getTimestamp())) {
+                    &bigramProperty)) {
                 LogUtils::logToJava(env, "Cannot add bigram to the new dict.");
                 return false;
             }
diff --git a/native/jni/src/suggest/core/dictionary/dictionary.cpp b/native/jni/src/suggest/core/dictionary/dictionary.cpp
index e288413..fdc8936 100644
--- a/native/jni/src/suggest/core/dictionary/dictionary.cpp
+++ b/native/jni/src/suggest/core/dictionary/dictionary.cpp
@@ -88,11 +88,10 @@
     mDictionaryStructureWithBufferPolicy->addUnigramWord(word, length, unigramProperty);
 }
 
-void Dictionary::addBigramWords(const int *const word0, const int length0, const int *const word1,
-        const int length1, const int probability, const int timestamp) {
+void Dictionary::addBigramWords(const int *const word0, const int length0,
+        const BigramProperty *const bigramProperty) {
     TimeKeeper::setCurrentTime();
-    mDictionaryStructureWithBufferPolicy->addBigramWords(word0, length0, word1, length1,
-            probability, timestamp);
+    mDictionaryStructureWithBufferPolicy->addBigramWords(word0, length0, bigramProperty);
 }
 
 void Dictionary::removeBigramWords(const int *const word0, const int length0,
diff --git a/native/jni/src/suggest/core/dictionary/dictionary.h b/native/jni/src/suggest/core/dictionary/dictionary.h
index b6149b3..f0a7e5b 100644
--- a/native/jni/src/suggest/core/dictionary/dictionary.h
+++ b/native/jni/src/suggest/core/dictionary/dictionary.h
@@ -76,8 +76,8 @@
     void addUnigramWord(const int *const codePoints, const int codePointCount,
             const UnigramProperty *const unigramProperty);
 
-    void addBigramWords(const int *const word0, const int length0, const int *const word1,
-            const int length1, const int probability, const int timestamp);
+    void addBigramWords(const int *const word0, const int length0,
+            const BigramProperty *const bigramProperty);
 
     void removeBigramWords(const int *const word0, const int length0, const int *const word1,
             const int length1);
diff --git a/native/jni/src/suggest/core/layout/proximity_info.cpp b/native/jni/src/suggest/core/layout/proximity_info.cpp
index c40a2bd..4c75a18 100644
--- a/native/jni/src/suggest/core/layout/proximity_info.cpp
+++ b/native/jni/src/suggest/core/layout/proximity_info.cpp
@@ -226,7 +226,7 @@
 // When the referencePointY is NOT_A_COORDINATE, this method calculates the return value without
 // using the line segment.
 int ProximityInfo::getKeyCenterYOfKeyIdG(
-        const int keyId,  const int referencePointY, const bool isGeometric) const {
+        const int keyId, const int referencePointY, const bool isGeometric) const {
     // TODO: Remove "isGeometric" and have separate "proximity_info"s for gesture and typing.
     if (keyId < 0) {
         return 0;
diff --git a/native/jni/src/suggest/core/layout/proximity_info_state_utils.h b/native/jni/src/suggest/core/layout/proximity_info_state_utils.h
index 71e83a8..211a797 100644
--- a/native/jni/src/suggest/core/layout/proximity_info_state_utils.h
+++ b/native/jni/src/suggest/core/layout/proximity_info_state_utils.h
@@ -56,7 +56,7 @@
             const std::vector<int> *const sampledLengthCache,
             const std::vector<int> *const sampledInputIndice,
             std::vector<float> *sampledSpeedRates, std::vector<float> *sampledDirections);
-    static void refreshBeelineSpeedRates(const int mostCommonKeyWidth,  const float averageSpeed,
+    static void refreshBeelineSpeedRates(const int mostCommonKeyWidth, const float averageSpeed,
             const int inputSize, const int *const xCoordinates, const int *const yCoordinates,
             const int *times, const int sampledInputSize,
             const std::vector<int> *const sampledInputXs,
diff --git a/native/jni/src/suggest/core/policy/dictionary_structure_with_buffer_policy.h b/native/jni/src/suggest/core/policy/dictionary_structure_with_buffer_policy.h
index 807f9b8..ce5a49f 100644
--- a/native/jni/src/suggest/core/policy/dictionary_structure_with_buffer_policy.h
+++ b/native/jni/src/suggest/core/policy/dictionary_structure_with_buffer_policy.h
@@ -73,8 +73,8 @@
             const UnigramProperty *const unigramProperty) = 0;
 
     // Returns whether the update was success or not.
-    virtual bool addBigramWords(const int *const word0, const int length0, const int *const word1,
-            const int length1, const int probability, const int timestamp) = 0;
+    virtual bool addBigramWords(const int *const word0, const int length0,
+            const BigramProperty *const bigramProperty) = 0;
 
     // Returns whether the update was success or not.
     virtual bool removeBigramWords(const int *const word0, const int length0,
diff --git a/native/jni/src/suggest/policyimpl/dictionary/bigram/bigram_list_read_write_utils.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/bigram/bigram_list_read_write_utils.cpp
similarity index 96%
rename from native/jni/src/suggest/policyimpl/dictionary/bigram/bigram_list_read_write_utils.cpp
rename to native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/bigram/bigram_list_read_write_utils.cpp
index 7d0d096..08b4e0b 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/bigram/bigram_list_read_write_utils.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/bigram/bigram_list_read_write_utils.cpp
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "suggest/policyimpl/dictionary/bigram/bigram_list_read_write_utils.h"
+#include "suggest/policyimpl/dictionary/structure/pt_common/bigram/bigram_list_read_write_utils.h"
 
 #include "suggest/policyimpl/dictionary/utils/byte_array_utils.h"
 #include "suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h"
diff --git a/native/jni/src/suggest/policyimpl/dictionary/bigram/bigram_list_read_write_utils.h b/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/bigram/bigram_list_read_write_utils.h
similarity index 100%
rename from native/jni/src/suggest/policyimpl/dictionary/bigram/bigram_list_read_write_utils.h
rename to native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/bigram/bigram_list_read_write_utils.h
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/dynamic_pt_updating_helper.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/dynamic_pt_updating_helper.cpp
index a527f03..9e57585 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/dynamic_pt_updating_helper.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/dynamic_pt_updating_helper.cpp
@@ -85,13 +85,13 @@
 }
 
 bool DynamicPtUpdatingHelper::addBigramWords(const int word0Pos, const int word1Pos,
-        const int probability, const int timestamp, bool *const outAddedNewBigram) {
+        const BigramProperty *const bigramProperty, bool *const outAddedNewBigram) {
     const PtNodeParams sourcePtNodeParams(
             mPtNodeReader->fetchNodeInfoInBufferFromPtNodePos(word0Pos));
     const PtNodeParams targetPtNodeParams(
             mPtNodeReader->fetchNodeInfoInBufferFromPtNodePos(word1Pos));
-    return mPtNodeWriter->addNewBigramEntry(&sourcePtNodeParams, &targetPtNodeParams, probability,
-            timestamp, outAddedNewBigram);
+    return mPtNodeWriter->addNewBigramEntry(&sourcePtNodeParams, &targetPtNodeParams,
+            bigramProperty, outAddedNewBigram);
 }
 
 // Remove a bigram relation from word0Pos to word1Pos.
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/dynamic_pt_updating_helper.h b/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/dynamic_pt_updating_helper.h
index 44914fe..f10d15a 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/dynamic_pt_updating_helper.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/dynamic_pt_updating_helper.h
@@ -22,6 +22,7 @@
 
 namespace latinime {
 
+class BigramProperty;
 class BufferWithExtendableBuffer;
 class DynamicPtReadingHelper;
 class PtNodeReader;
@@ -42,8 +43,8 @@
             const UnigramProperty *const unigramProperty, bool *const outAddedNewUnigram);
 
     // Add a bigram relation from word0Pos to word1Pos.
-    bool addBigramWords(const int word0Pos, const int word1Pos, const int probability,
-            const int timestamp, bool *const outAddedNewBigram);
+    bool addBigramWords(const int word0Pos, const int word1Pos,
+            const BigramProperty *const bigramProperty, bool *const outAddedNewBigram);
 
     // Remove a bigram relation from word0Pos to word1Pos.
     bool removeBigramWords(const int word0Pos, const int word1Pos);
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/pt_node_writer.h b/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/pt_node_writer.h
index cbca3fe..a8029f7 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/pt_node_writer.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/pt_node_writer.h
@@ -24,6 +24,7 @@
 
 namespace latinime {
 
+class BigramProperty;
 class UnigramProperty;
 
 // Interface class used to write PtNode information.
@@ -70,7 +71,7 @@
             const UnigramProperty *const unigramProperty, int *const ptNodeWritingPos) = 0;
 
     virtual bool addNewBigramEntry(const PtNodeParams *const sourcePtNodeParams,
-            const PtNodeParams *const targetPtNodeParam, const int probability, const int timestamp,
+            const PtNodeParams *const targetPtNodeParam, const BigramProperty *const bigramProperty,
             bool *const outAddedNewBigram) = 0;
 
     virtual bool removeBigramEntry(const PtNodeParams *const sourcePtNodeParams,
diff --git a/native/jni/src/suggest/policyimpl/dictionary/shortcut/shortcut_list_reading_utils.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/shortcut/shortcut_list_reading_utils.cpp
similarity index 90%
rename from native/jni/src/suggest/policyimpl/dictionary/shortcut/shortcut_list_reading_utils.cpp
rename to native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/shortcut/shortcut_list_reading_utils.cpp
index 847dcde..91c7694 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/shortcut/shortcut_list_reading_utils.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/shortcut/shortcut_list_reading_utils.cpp
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-#include "suggest/policyimpl/dictionary/shortcut/shortcut_list_reading_utils.h"
+#include "suggest/policyimpl/dictionary/structure/pt_common/shortcut/shortcut_list_reading_utils.h"
 
 #include "suggest/policyimpl/dictionary/utils/byte_array_utils.h"
 
@@ -44,7 +44,7 @@
 }
 
 /* static */ int ShortcutListReadingUtils::readShortcutTarget(
-        const uint8_t *const dictRoot, const int maxLength,  int *const outWord, int *const pos) {
+        const uint8_t *const dictRoot, const int maxLength, int *const outWord, int *const pos) {
     return ByteArrayUtils::readStringAndAdvancePosition(dictRoot, maxLength, outWord, pos);
 }
 
diff --git a/native/jni/src/suggest/policyimpl/dictionary/shortcut/shortcut_list_reading_utils.h b/native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/shortcut/shortcut_list_reading_utils.h
similarity index 100%
rename from native/jni/src/suggest/policyimpl/dictionary/shortcut/shortcut_list_reading_utils.h
rename to native/jni/src/suggest/policyimpl/dictionary/structure/pt_common/shortcut/shortcut_list_reading_utils.h
diff --git a/native/jni/src/suggest/policyimpl/dictionary/bigram/bigram_list_policy.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v2/bigram/bigram_list_policy.h
similarity index 94%
rename from native/jni/src/suggest/policyimpl/dictionary/bigram/bigram_list_policy.h
rename to native/jni/src/suggest/policyimpl/dictionary/structure/v2/bigram/bigram_list_policy.h
index a898e2a..00bb502 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/bigram/bigram_list_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v2/bigram/bigram_list_policy.h
@@ -21,7 +21,7 @@
 
 #include "defines.h"
 #include "suggest/core/policy/dictionary_bigrams_structure_policy.h"
-#include "suggest/policyimpl/dictionary/bigram/bigram_list_read_write_utils.h"
+#include "suggest/policyimpl/dictionary/structure/pt_common/bigram/bigram_list_read_write_utils.h"
 
 namespace latinime {
 
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v2/patricia_trie_policy.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v2/patricia_trie_policy.h
index 85f4660..54d1e0f 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v2/patricia_trie_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v2/patricia_trie_policy.h
@@ -22,9 +22,9 @@
 
 #include "defines.h"
 #include "suggest/core/policy/dictionary_structure_with_buffer_policy.h"
-#include "suggest/policyimpl/dictionary/bigram/bigram_list_policy.h"
 #include "suggest/policyimpl/dictionary/header/header_policy.h"
-#include "suggest/policyimpl/dictionary/shortcut/shortcut_list_policy.h"
+#include "suggest/policyimpl/dictionary/structure/v2/bigram/bigram_list_policy.h"
+#include "suggest/policyimpl/dictionary/structure/v2/shortcut/shortcut_list_policy.h"
 #include "suggest/policyimpl/dictionary/structure/v2/ver2_patricia_trie_node_reader.h"
 #include "suggest/policyimpl/dictionary/structure/v2/ver2_pt_node_array_reader.h"
 #include "suggest/policyimpl/dictionary/utils/format_utils.h"
@@ -88,8 +88,8 @@
         return false;
     }
 
-    bool addBigramWords(const int *const word0, const int length0, const int *const word1,
-            const int length1, const int probability, const int timestamp) {
+    bool addBigramWords(const int *const word0, const int length0,
+            const BigramProperty *const bigramProperty) {
         // This method should not be called for non-updatable dictionary.
         AKLOGI("Warning: addBigramWords() is called for non-updatable dictionary.");
         return false;
diff --git a/native/jni/src/suggest/policyimpl/dictionary/shortcut/shortcut_list_policy.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v2/shortcut/shortcut_list_policy.h
similarity index 95%
rename from native/jni/src/suggest/policyimpl/dictionary/shortcut/shortcut_list_policy.h
rename to native/jni/src/suggest/policyimpl/dictionary/structure/v2/shortcut/shortcut_list_policy.h
index 6d2b477..8e16ccc 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/shortcut/shortcut_list_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v2/shortcut/shortcut_list_policy.h
@@ -21,7 +21,7 @@
 
 #include "defines.h"
 #include "suggest/core/policy/dictionary_shortcuts_structure_policy.h"
-#include "suggest/policyimpl/dictionary/shortcut/shortcut_list_reading_utils.h"
+#include "suggest/policyimpl/dictionary/structure/pt_common/shortcut/shortcut_list_reading_utils.h"
 
 namespace latinime {
 
diff --git a/native/jni/src/suggest/policyimpl/dictionary/bigram/ver4_bigram_list_policy.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/bigram/ver4_bigram_list_policy.cpp
similarity index 93%
rename from native/jni/src/suggest/policyimpl/dictionary/bigram/ver4_bigram_list_policy.cpp
rename to native/jni/src/suggest/policyimpl/dictionary/structure/v4/bigram/ver4_bigram_list_policy.cpp
index 1645039..7a52fd1 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/bigram/ver4_bigram_list_policy.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/bigram/ver4_bigram_list_policy.cpp
@@ -14,10 +14,11 @@
  * limitations under the License.
  */
 
-#include "suggest/policyimpl/dictionary/bigram/ver4_bigram_list_policy.h"
+#include "suggest/policyimpl/dictionary/structure/v4/bigram/ver4_bigram_list_policy.h"
 
-#include "suggest/policyimpl/dictionary/bigram/bigram_list_read_write_utils.h"
+#include "suggest/core/dictionary/property/bigram_property.h"
 #include "suggest/policyimpl/dictionary/header/header_policy.h"
+#include "suggest/policyimpl/dictionary/structure/pt_common/bigram/bigram_list_read_write_utils.h"
 #include "suggest/policyimpl/dictionary/structure/v4/content/bigram_dict_content.h"
 #include "suggest/policyimpl/dictionary/structure/v4/content/terminal_position_lookup_table.h"
 #include "suggest/policyimpl/dictionary/structure/v4/ver4_dict_constants.h"
@@ -49,13 +50,12 @@
 }
 
 bool Ver4BigramListPolicy::addNewEntry(const int terminalId, const int newTargetTerminalId,
-        const int newProbability, const int timestamp, bool *const outAddedNewEntry) {
+        const BigramProperty *const bigramProperty, bool *const outAddedNewEntry) {
     // 1. The word has no bigrams yet.
     // 2. The word has bigrams, and there is the target in the list.
     // 3. The word has bigrams, and there is an invalid entry that can be reclaimed.
     // 4. The word has bigrams. We have to append new bigram entry to the list.
     // 5. Same as 4, but the list is the last entry of the content file.
-
     if (outAddedNewEntry) {
         *outAddedNewEntry = false;
     }
@@ -69,7 +69,7 @@
         const BigramEntry newBigramEntry(false /* hasNext */, NOT_A_PROBABILITY,
                 newTargetTerminalId);
         const BigramEntry bigramEntryToWrite = createUpdatedBigramEntryFrom(&newBigramEntry,
-                newProbability, timestamp);
+                bigramProperty);
         // Write an entry.
         const int writingPos =  mBigramDictContent->getBigramListHeadPos(terminalId);
         if (!mBigramDictContent->writeBigramEntry(&bigramEntryToWrite, writingPos)) {
@@ -102,7 +102,7 @@
         const BigramEntry newBigramEntry(false /* hasNext */, NOT_A_PROBABILITY,
                 newTargetTerminalId);
         const BigramEntry bigramEntryToWrite = createUpdatedBigramEntryFrom(
-                &newBigramEntry, newProbability, timestamp);
+                &newBigramEntry, bigramProperty);
         if (!mBigramDictContent->writeBigramEntryAtTail(&bigramEntryToWrite)) {
             return false;
         }
@@ -128,7 +128,7 @@
     const BigramEntry updatedBigramEntry =
             originalBigramEntry.updateTargetTerminalIdAndGetEntry(newTargetTerminalId);
     const BigramEntry bigramEntryToWrite = createUpdatedBigramEntryFrom(
-            &updatedBigramEntry, newProbability, timestamp);
+            &updatedBigramEntry, bigramProperty);
     return mBigramDictContent->writeBigramEntry(&bigramEntryToWrite, entryPosToUpdate);
 }
 
@@ -253,19 +253,19 @@
 }
 
 const BigramEntry Ver4BigramListPolicy::createUpdatedBigramEntryFrom(
-        const BigramEntry *const originalBigramEntry, const int newProbability,
-        const int timestamp) const {
+        const BigramEntry *const originalBigramEntry,
+        const BigramProperty *const bigramProperty) const {
     // TODO: Consolidate historical info and probability.
     if (mHeaderPolicy->hasHistoricalInfoOfWords()) {
-        // Use 1 for count to indicate the bigram has inputed.
-        const HistoricalInfo historicalInfoForUpdate(timestamp, 0 /* level */, 1 /* count */);
+        const HistoricalInfo historicalInfoForUpdate(bigramProperty->getTimestamp(),
+                bigramProperty->getLevel(), bigramProperty->getCount());
         const HistoricalInfo updatedHistoricalInfo =
                 ForgettingCurveUtils::createUpdatedHistoricalInfo(
-                        originalBigramEntry->getHistoricalInfo(), newProbability,
+                        originalBigramEntry->getHistoricalInfo(), bigramProperty->getProbability(),
                         &historicalInfoForUpdate, mHeaderPolicy);
         return originalBigramEntry->updateHistoricalInfoAndGetEntry(&updatedHistoricalInfo);
     } else {
-        return originalBigramEntry->updateProbabilityAndGetEntry(newProbability);
+        return originalBigramEntry->updateProbabilityAndGetEntry(bigramProperty->getProbability());
     }
 }
 
diff --git a/native/jni/src/suggest/policyimpl/dictionary/bigram/ver4_bigram_list_policy.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/bigram/ver4_bigram_list_policy.h
similarity index 93%
rename from native/jni/src/suggest/policyimpl/dictionary/bigram/ver4_bigram_list_policy.h
rename to native/jni/src/suggest/policyimpl/dictionary/structure/v4/bigram/ver4_bigram_list_policy.h
index c1f3335..1613941 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/bigram/ver4_bigram_list_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/bigram/ver4_bigram_list_policy.h
@@ -24,6 +24,7 @@
 namespace latinime {
 
 class BigramDictContent;
+class BigramProperty;
 class HeaderPolicy;
 class TerminalPositionLookupTable;
 
@@ -43,8 +44,8 @@
         // Do nothing because we don't need to skip bigram lists in ver4 dictionaries.
     }
 
-    bool addNewEntry(const int terminalId, const int newTargetTerminalId, const int newProbability,
-            const int timestamp, bool *const outAddedNewEntry);
+    bool addNewEntry(const int terminalId, const int newTargetTerminalId,
+            const BigramProperty *const bigramProperty, bool *const outAddedNewEntry);
 
     bool removeEntry(const int terminalId, const int targetTerminalId);
 
@@ -60,7 +61,7 @@
             int *const outTailEntryPos) const;
 
     const BigramEntry createUpdatedBigramEntryFrom(const BigramEntry *const originalBigramEntry,
-            const int newProbability, const int timestamp) const;
+            const BigramProperty *const bigramProperty) const;
 
     bool updateHasNextFlag(const bool hasNext, const int bigramEntryPos);
 
diff --git a/native/jni/src/suggest/policyimpl/dictionary/shortcut/ver4_shortcut_list_policy.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/shortcut/ver4_shortcut_list_policy.h
similarity index 97%
rename from native/jni/src/suggest/policyimpl/dictionary/shortcut/ver4_shortcut_list_policy.h
rename to native/jni/src/suggest/policyimpl/dictionary/structure/v4/shortcut/ver4_shortcut_list_policy.h
index fe98461..7902735 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/shortcut/ver4_shortcut_list_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/shortcut/ver4_shortcut_list_policy.h
@@ -19,7 +19,7 @@
 
 #include "defines.h"
 #include "suggest/core/policy/dictionary_shortcuts_structure_policy.h"
-#include "suggest/policyimpl/dictionary/shortcut/shortcut_list_reading_utils.h"
+#include "suggest/policyimpl/dictionary/structure/pt_common/shortcut/shortcut_list_reading_utils.h"
 #include "suggest/policyimpl/dictionary/structure/v4/content/shortcut_dict_content.h"
 #include "suggest/policyimpl/dictionary/structure/v4/content/terminal_position_lookup_table.h"
 
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_reader.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_reader.cpp
index 67420a2..0a435e9 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_reader.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_reader.cpp
@@ -95,4 +95,4 @@
     }
 }
 
-}
+} // namespace latinime
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_writer.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_writer.cpp
index cc3a24a..f89d3d7 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_writer.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_writer.cpp
@@ -17,13 +17,13 @@
 #include "suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_writer.h"
 
 #include "suggest/core/dictionary/property/unigram_property.h"
-#include "suggest/policyimpl/dictionary/bigram/ver4_bigram_list_policy.h"
 #include "suggest/policyimpl/dictionary/header/header_policy.h"
-#include "suggest/policyimpl/dictionary/shortcut/ver4_shortcut_list_policy.h"
 #include "suggest/policyimpl/dictionary/structure/pt_common/dynamic_pt_reading_utils.h"
 #include "suggest/policyimpl/dictionary/structure/pt_common/dynamic_pt_writing_utils.h"
 #include "suggest/policyimpl/dictionary/structure/pt_common/patricia_trie_reading_utils.h"
+#include "suggest/policyimpl/dictionary/structure/v4/bigram/ver4_bigram_list_policy.h"
 #include "suggest/policyimpl/dictionary/structure/v4/content/probability_entry.h"
+#include "suggest/policyimpl/dictionary/structure/v4/shortcut/ver4_shortcut_list_policy.h"
 #include "suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_reader.h"
 #include "suggest/policyimpl/dictionary/structure/v4/ver4_dict_buffers.h"
 #include "suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h"
@@ -76,7 +76,7 @@
             PatriciaTrieReadingUtils::getFlagsAndAdvancePosition(dictBuf, &pos);
     const PatriciaTrieReadingUtils::NodeFlags updatedFlags =
             DynamicPtReadingUtils::updateAndGetFlags(originalFlags, true /* isMoved */,
-                    false /* isDeleted */,  false /* willBecomeNonTerminal */);
+                    false /* isDeleted */, false /* willBecomeNonTerminal */);
     int writingPos = toBeUpdatedPtNodeParams->getHeadPos();
     // Update flags.
     if (!DynamicPtWritingUtils::writeFlagsAndAdvancePosition(mTrieBuffer, updatedFlags,
@@ -223,11 +223,10 @@
 }
 
 bool Ver4PatriciaTrieNodeWriter::addNewBigramEntry(
-        const PtNodeParams *const sourcePtNodeParams,
-        const PtNodeParams *const targetPtNodeParam, const int probability, const int timestamp,
-        bool *const outAddedNewBigram) {
+        const PtNodeParams *const sourcePtNodeParams, const PtNodeParams *const targetPtNodeParam,
+        const BigramProperty *const bigramProperty, bool *const outAddedNewBigram) {
     if (!mBigramPolicy->addNewEntry(sourcePtNodeParams->getTerminalId(),
-            targetPtNodeParam->getTerminalId(), probability, timestamp, outAddedNewBigram)) {
+            targetPtNodeParam->getTerminalId(), bigramProperty, outAddedNewBigram)) {
         AKLOGE("Cannot add new bigram entry. terminalId: %d, targetTerminalId: %d",
                 sourcePtNodeParams->getTerminalId(), targetPtNodeParam->getTerminalId());
         return false;
@@ -416,4 +415,4 @@
     return true;
 }
 
-}
+} // namespace latinime
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_writer.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_writer.h
index f20d3a2..e90bc44 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_writer.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_writer.h
@@ -76,7 +76,7 @@
             const UnigramProperty *const unigramProperty, int *const ptNodeWritingPos);
 
     virtual bool addNewBigramEntry(const PtNodeParams *const sourcePtNodeParams,
-            const PtNodeParams *const targetPtNodeParam, const int probability, const int timestamp,
+            const PtNodeParams *const targetPtNodeParam, const BigramProperty *const bigramProperty,
             bool *const outAddedNewBigram);
 
     virtual bool removeBigramEntry(const PtNodeParams *const sourcePtNodeParams,
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.cpp
index 9999e06..2fb3dec 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.cpp
@@ -209,8 +209,7 @@
 }
 
 bool Ver4PatriciaTriePolicy::addBigramWords(const int *const word0, const int length0,
-        const int *const word1, const int length1, const int probability,
-        const int timestamp) {
+        const BigramProperty *const bigramProperty) {
     if (!mBuffers->isUpdatable()) {
         AKLOGI("Warning: addBigramWords() is called for non-updatable dictionary.");
         return false;
@@ -220,9 +219,10 @@
                 mDictBuffer->getTailPosition());
         return false;
     }
-    if (length0 > MAX_WORD_LENGTH || length1 > MAX_WORD_LENGTH) {
+    if (length0 > MAX_WORD_LENGTH
+            || bigramProperty->getTargetCodePoints()->size() > MAX_WORD_LENGTH) {
         AKLOGE("Either src word or target word is too long to insert the bigram to the dictionary. "
-                "length0: %d, length1: %d", length0, length1);
+                "length0: %d, length1: %d", length0, bigramProperty->getTargetCodePoints()->size());
         return false;
     }
     const int word0Pos = getTerminalPtNodePositionOfWord(word0, length0,
@@ -230,14 +230,14 @@
     if (word0Pos == NOT_A_DICT_POS) {
         return false;
     }
-    const int word1Pos = getTerminalPtNodePositionOfWord(word1, length1,
-            false /* forceLowerCaseSearch */);
+    const int word1Pos = getTerminalPtNodePositionOfWord(
+            bigramProperty->getTargetCodePoints()->data(),
+            bigramProperty->getTargetCodePoints()->size(), false /* forceLowerCaseSearch */);
     if (word1Pos == NOT_A_DICT_POS) {
         return false;
     }
     bool addedNewBigram = false;
-    if (mUpdatingHelper.addBigramWords(word0Pos, word1Pos, probability, timestamp,
-            &addedNewBigram)) {
+    if (mUpdatingHelper.addBigramWords(word0Pos, word1Pos, bigramProperty, &addedNewBigram)) {
         if (addedNewBigram) {
             mBigramCount++;
         }
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.h
index 8f981de..b785764 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.h
@@ -21,10 +21,10 @@
 
 #include "defines.h"
 #include "suggest/core/policy/dictionary_structure_with_buffer_policy.h"
-#include "suggest/policyimpl/dictionary/bigram/ver4_bigram_list_policy.h"
 #include "suggest/policyimpl/dictionary/header/header_policy.h"
-#include "suggest/policyimpl/dictionary/shortcut/ver4_shortcut_list_policy.h"
 #include "suggest/policyimpl/dictionary/structure/pt_common/dynamic_pt_updating_helper.h"
+#include "suggest/policyimpl/dictionary/structure/v4/bigram/ver4_bigram_list_policy.h"
+#include "suggest/policyimpl/dictionary/structure/v4/shortcut/ver4_shortcut_list_policy.h"
 #include "suggest/policyimpl/dictionary/structure/v4/ver4_dict_buffers.h"
 #include "suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_reader.h"
 #include "suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_writer.h"
@@ -93,8 +93,8 @@
     bool addUnigramWord(const int *const word, const int length,
             const UnigramProperty *const unigramProperty);
 
-    bool addBigramWords(const int *const word0, const int length0, const int *const word1,
-            const int length1, const int probability, const int timestamp);
+    bool addBigramWords(const int *const word0, const int length0,
+            const BigramProperty *const bigramProperty);
 
     bool removeBigramWords(const int *const word0, const int length0, const int *const word1,
             const int length1);
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_writing_helper.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_writing_helper.cpp
index 12298d9..f31c502 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_writing_helper.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_writing_helper.cpp
@@ -19,9 +19,9 @@
 #include <cstring>
 #include <queue>
 
-#include "suggest/policyimpl/dictionary/bigram/ver4_bigram_list_policy.h"
 #include "suggest/policyimpl/dictionary/header/header_policy.h"
-#include "suggest/policyimpl/dictionary/shortcut/ver4_shortcut_list_policy.h"
+#include "suggest/policyimpl/dictionary/structure/v4/bigram/ver4_bigram_list_policy.h"
+#include "suggest/policyimpl/dictionary/structure/v4/shortcut/ver4_shortcut_list_policy.h"
 #include "suggest/policyimpl/dictionary/structure/v4/ver4_dict_buffers.h"
 #include "suggest/policyimpl/dictionary/structure/v4/ver4_dict_constants.h"
 #include "suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_node_reader.h"
diff --git a/tests/src/com/android/inputmethod/latin/BinaryDictionaryDecayingTests.java b/tests/src/com/android/inputmethod/latin/BinaryDictionaryDecayingTests.java
index aed24c5..35d9a4e 100644
--- a/tests/src/com/android/inputmethod/latin/BinaryDictionaryDecayingTests.java
+++ b/tests/src/com/android/inputmethod/latin/BinaryDictionaryDecayingTests.java
@@ -580,7 +580,6 @@
         final BinaryDictionary binaryDictionary = new BinaryDictionary(dictFile.getAbsolutePath(),
                 0 /* offset */, dictFile.length(), true /* useFullEditDistance */,
                 Locale.getDefault(), TEST_LOCALE, true /* isUpdatable */);
-        // TODO: Add tests for bigrams when the implementation gets ready.
         addUnigramWord(binaryDictionary, "aaa", DUMMY_PROBABILITY);
         assertTrue(binaryDictionary.isValidWord("aaa"));
         addUnigramWord(binaryDictionary, "bbb", Dictionary.NOT_A_PROBABILITY);
@@ -590,6 +589,11 @@
         addUnigramWord(binaryDictionary, "ccc", DUMMY_PROBABILITY);
         addUnigramWord(binaryDictionary, "ccc", DUMMY_PROBABILITY);
         addUnigramWord(binaryDictionary, "ccc", DUMMY_PROBABILITY);
+        addUnigramWord(binaryDictionary, "abc", DUMMY_PROBABILITY);
+        addBigramWords(binaryDictionary, "aaa", "abc", DUMMY_PROBABILITY);
+        assertTrue(binaryDictionary.isValidBigram("aaa", "abc"));
+        addBigramWords(binaryDictionary, "aaa", "bbb", Dictionary.NOT_A_PROBABILITY);
+        assertFalse(binaryDictionary.isValidBigram("aaa", "bbb"));
 
         assertEquals(fromFormatVersion, binaryDictionary.getFormatVersion());
         assertTrue(binaryDictionary.migrateTo(toFormatVersion));
@@ -600,6 +604,10 @@
         assertTrue(binaryDictionary.getFrequency("aaa") < binaryDictionary.getFrequency("ccc"));
         addUnigramWord(binaryDictionary, "bbb", Dictionary.NOT_A_PROBABILITY);
         assertTrue(binaryDictionary.isValidWord("bbb"));
+        assertTrue(binaryDictionary.isValidBigram("aaa", "abc"));
+        assertFalse(binaryDictionary.isValidBigram("aaa", "bbb"));
+        addBigramWords(binaryDictionary, "aaa", "bbb", Dictionary.NOT_A_PROBABILITY);
+        assertTrue(binaryDictionary.isValidBigram("aaa", "bbb"));
         binaryDictionary.close();
         dictFile.delete();
     }
diff --git a/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java b/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java
index 9ceafa7..770e76e 100644
--- a/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java
+++ b/tests/src/com/android/inputmethod/latin/BinaryDictionaryTests.java
@@ -1245,6 +1245,12 @@
         addUnigramWord(binaryDictionary, "bbb", unigramProbability);
         final int bigramProbability = 10;
         addBigramWords(binaryDictionary, "aaa", "bbb", bigramProbability);
+        final int shortcutProbability = 10;
+        binaryDictionary.addUnigramWord("ccc", unigramProbability, "xxx", shortcutProbability,
+                false /* isNotAWord */, false /* isBlacklisted */, 0 /* timestamp */);
+        binaryDictionary.addUnigramWord("ddd", unigramProbability, null /* shortcutTarget */,
+                Dictionary.NOT_A_PROBABILITY, true /* isNotAWord */,
+                true /* isBlacklisted */, 0 /* timestamp */);
         assertEquals(unigramProbability, binaryDictionary.getFrequency("aaa"));
         assertEquals(unigramProbability, binaryDictionary.getFrequency("bbb"));
         assertTrue(binaryDictionary.isValidBigram("aaa", "bbb"));
@@ -1256,5 +1262,84 @@
         assertEquals(unigramProbability, binaryDictionary.getFrequency("bbb"));
         // TODO: Add tests for bigram frequency when the implementation gets ready.
         assertTrue(binaryDictionary.isValidBigram("aaa", "bbb"));
+        WordProperty wordProperty = binaryDictionary.getWordProperty("ccc");
+        assertEquals(1, wordProperty.mShortcutTargets.size());
+        assertEquals("xxx", wordProperty.mShortcutTargets.get(0).mWord);
+        wordProperty = binaryDictionary.getWordProperty("ddd");
+        assertTrue(wordProperty.mIsBlacklistEntry);
+        assertTrue(wordProperty.mIsNotAWord);
+    }
+
+    public void testLargeDictMigration() {
+        testLargeDictMigration(FormatSpec.VERSION4_ONLY_FOR_TESTING, FormatSpec.VERSION4);
+    }
+
+    private void testLargeDictMigration(final int fromFormatVersion, final int toFormatVersion) {
+        final int UNIGRAM_COUNT = 3000;
+        final int BIGRAM_COUNT = 3000;
+        final int codePointSetSize = 50;
+        final long seed = System.currentTimeMillis();
+        final Random random = new Random(seed);
+
+        File dictFile = null;
+        try {
+            dictFile = createEmptyDictionaryAndGetFile("TestBinaryDictionary", fromFormatVersion);
+        } catch (IOException e) {
+            fail("IOException while writing an initial dictionary : " + e);
+        }
+        final BinaryDictionary binaryDictionary = new BinaryDictionary(dictFile.getAbsolutePath(),
+                0 /* offset */, dictFile.length(), true /* useFullEditDistance */,
+                Locale.getDefault(), TEST_LOCALE, true /* isUpdatable */);
+
+        final ArrayList<String> words = new ArrayList<String>();
+        final ArrayList<Pair<String, String>> bigrams = new ArrayList<Pair<String,String>>();
+        final int[] codePointSet = CodePointUtils.generateCodePointSet(codePointSetSize, random);
+        final HashMap<String, Integer> unigramProbabilities = new HashMap<String, Integer>();
+        final HashMap<Pair<String, String>, Integer> bigramProbabilities =
+                new HashMap<Pair<String, String>, Integer>();
+
+        for (int i = 0; i < UNIGRAM_COUNT; i++) {
+            final String word = CodePointUtils.generateWord(random, codePointSet);
+            final int unigramProbability = random.nextInt(0xFF);
+            addUnigramWord(binaryDictionary, word, unigramProbability);
+            if (binaryDictionary.needsToRunGC(true /* mindsBlockByGC */)) {
+                binaryDictionary.flushWithGC();
+            }
+            words.add(word);
+            unigramProbabilities.put(word, unigramProbability);
+        }
+
+        for (int i = 0; i < BIGRAM_COUNT; i++) {
+            final int word0Index = random.nextInt(words.size());
+            final int word1Index = random.nextInt(words.size());
+            if (word0Index == word1Index) {
+                continue;
+            }
+            final String word0 = words.get(word0Index);
+            final String word1 = words.get(word1Index);
+            final int bigramProbability = random.nextInt(0xF);
+            binaryDictionary.addBigramWords(word0, word1, bigramProbability,
+                    BinaryDictionary.NOT_A_VALID_TIMESTAMP);
+            if (binaryDictionary.needsToRunGC(true /* mindsBlockByGC */)) {
+                binaryDictionary.flushWithGC();
+            }
+            final Pair<String, String> bigram = new Pair<String, String>(word0, word1);
+            bigrams.add(bigram);
+            bigramProbabilities.put(bigram, bigramProbability);
+        }
+        assertTrue(binaryDictionary.migrateTo(toFormatVersion));
+
+        for (final String word : words) {
+            assertEquals((int)unigramProbabilities.get(word), binaryDictionary.getFrequency(word));
+        }
+        assertEquals(unigramProbabilities.size(), Integer.parseInt(
+                binaryDictionary.getPropertyForTest(BinaryDictionary.UNIGRAM_COUNT_QUERY)));
+
+        for (final Pair<String, String> bigram : bigrams) {
+            // TODO: Add tests for bigram frequency when the implementation gets ready.
+            assertTrue(binaryDictionary.isValidBigram(bigram.first, bigram.second));
+        }
+        assertEquals(bigramProbabilities.size(), Integer.parseInt(
+                binaryDictionary.getPropertyForTest(BinaryDictionary.BIGRAM_COUNT_QUERY)));
     }
 }