diff --git a/java/res/values/strings.xml b/java/res/values/strings.xml
index 35dd3e0..70a5b7e 100644
--- a/java/res/values/strings.xml
+++ b/java/res/values/strings.xml
@@ -85,6 +85,11 @@
     <!-- Description for auto completion -->
     <string name="auto_complete_summary">Spacebar and punctuation automatically insert highlighted word</string>
     
+    <!-- Option to enable bigram completion -->
+    <string name="bigram_suggestion">Bigram Suggestions</string>
+    <!-- Description for auto completion -->
+    <string name="bigram_suggestion_summary">Use previous word to improve suggestion</string>
+
     <!-- Array of prediction modes -->
     <string-array name="prediction_modes">
         <item>None</item>
diff --git a/java/res/xml/prefs.xml b/java/res/xml/prefs.xml
index 535b63f..c93fe0a 100644
--- a/java/res/xml/prefs.xml
+++ b/java/res/xml/prefs.xml
@@ -81,6 +81,14 @@
             android:defaultValue="@bool/enable_autocorrect"
             android:dependency="show_suggestions"
             />
-            
+
+        <CheckBoxPreference
+            android:key="bigram_suggestion"
+            android:title="@string/bigram_suggestion"
+            android:summary="@string/bigram_suggestion_summary"
+            android:persistent="true"
+            android:defaultValue="true"
+            android:dependency="auto_complete"
+            />
     </PreferenceCategory>            
 </PreferenceScreen>
diff --git a/java/src/com/android/inputmethod/latin/BinaryDictionary.java b/java/src/com/android/inputmethod/latin/BinaryDictionary.java
index 6473f45..8d23630 100644
--- a/java/src/com/android/inputmethod/latin/BinaryDictionary.java
+++ b/java/src/com/android/inputmethod/latin/BinaryDictionary.java
@@ -33,9 +33,9 @@
 public class BinaryDictionary extends Dictionary {
 
     private static final String TAG = "BinaryDictionary";
-    public static final int MAX_WORD_LENGTH = 48;
     private static final int MAX_ALTERNATIVES = 16;
     private static final int MAX_WORDS = 16;
+    private static final int MAX_BIGRAMS = 255; // TODO Probably don't need all 255
 
     private static final int TYPED_LETTER_MULTIPLIER = 2;
     private static final boolean ENABLE_MISSED_CHARACTERS = true;
@@ -44,7 +44,9 @@
     private int mDictLength;
     private int[] mInputCodes = new int[MAX_WORD_LENGTH * MAX_ALTERNATIVES];
     private char[] mOutputChars = new char[MAX_WORD_LENGTH * MAX_WORDS];
+    private char[] mOutputChars_bigrams = new char[MAX_WORD_LENGTH * MAX_BIGRAMS];
     private int[] mFrequencies = new int[MAX_WORDS];
+    private int[] mFrequencies_bigrams = new int[MAX_BIGRAMS];
     // Keep a reference to the native dict direct buffer in Java to avoid
     // unexpected deallocation of the direct buffer.
     private ByteBuffer mNativeDictDirectBuffer;
@@ -71,7 +73,7 @@
     /**
      * Create a dictionary from a byte buffer. This is used for testing.
      * @param context application context for reading resources
-     * @param resId the resource containing the raw binary dictionary
+     * @param byteBuffer a ByteBuffer containing the binary dictionary
      */
     public BinaryDictionary(Context context, ByteBuffer byteBuffer) {
         if (byteBuffer != null) {
@@ -95,6 +97,8 @@
             char[] outputChars, int[] frequencies,
             int maxWordLength, int maxWords, int maxAlternatives, int skipPos,
             int[] nextLettersFrequencies, int nextLettersSize);
+    private native int getBigramsNative(int nativeData, char[] prevWord, int prevWordLength,
+            char[] outputChars, int[] frequencies, int maxWordLength, int maxBigrams);
 
     private final void loadDictionary(Context context, int resId) {
         InputStream is = context.getResources().openRawResource(resId);
@@ -122,6 +126,30 @@
     }
 
     @Override
+    public void getBigrams(final WordComposer composer, final CharSequence previousWord,
+            final WordCallback callback, int[] nextLettersFrequencies) {
+
+        char[] chars = previousWord.toString().toCharArray();
+        Arrays.fill(mOutputChars_bigrams, (char) 0);
+        Arrays.fill(mFrequencies_bigrams, 0);
+
+        int count = getBigramsNative(mNativeDict, chars, chars.length, mOutputChars_bigrams,
+                mFrequencies_bigrams, MAX_WORD_LENGTH, MAX_BIGRAMS);
+        for (int j = 0; j < count; j++) {
+            if (mFrequencies_bigrams[j] < 1) break;
+            int start = j * MAX_WORD_LENGTH;
+            int len = 0;
+            while (mOutputChars_bigrams[start + len] != 0) {
+                len++;
+            }
+            if (len > 0) {
+                callback.addWord(mOutputChars_bigrams, start, len, mFrequencies_bigrams[j],
+                        DataType.BIGRAM);
+            }
+        }
+    }
+
+    @Override
     public void getWords(final WordComposer codes, final WordCallback callback,
             int[] nextLettersFrequencies) {
         final int codesSize = codes.size();
@@ -166,7 +194,7 @@
                 len++;
             }
             if (len > 0) {
-                callback.addWord(mOutputChars, start, len, mFrequencies[j]);
+                callback.addWord(mOutputChars, start, len, mFrequencies[j], DataType.UNIGRAM);
             }
         }
     }
diff --git a/java/src/com/android/inputmethod/latin/Dictionary.java b/java/src/com/android/inputmethod/latin/Dictionary.java
index e7b5266..54317c8 100644
--- a/java/src/com/android/inputmethod/latin/Dictionary.java
+++ b/java/src/com/android/inputmethod/latin/Dictionary.java
@@ -21,7 +21,9 @@
  * strokes.
  */
 abstract public class Dictionary {
-    
+
+    protected static final int MAX_WORD_LENGTH = 48;
+
     /**
      * Whether or not to replicate the typed word in the suggested list, even if it's valid.
      */
@@ -31,7 +33,11 @@
      * The weight to give to a word if it's length is the same as the number of typed characters.
      */
     protected static final int FULL_WORD_FREQ_MULTIPLIER = 2;
-    
+
+    public static enum DataType {
+        UNIGRAM, BIGRAM
+    }
+
     /**
      * Interface to be implemented by classes requesting words to be fetched from the dictionary.
      * @see #getWords(WordComposer, WordCallback)
@@ -45,9 +51,11 @@
          * @param wordLength length of valid characters in the character array
          * @param frequency the frequency of occurence. This is normalized between 1 and 255, but
          * can exceed those limits
+         * @param dataType tells type of this data
          * @return true if the word was added, false if no more words are required
          */
-        boolean addWord(char[] word, int wordOffset, int wordLength, int frequency);
+        boolean addWord(char[] word, int wordOffset, int wordLength, int frequency,
+                DataType dataType);
     }
 
     /**
@@ -65,6 +73,21 @@
             int[] nextLettersFrequencies);
 
     /**
+     * Searches for pairs in the bigram dictionary that matches the previous word and all the
+     * possible words following are added through the callback object.
+     * @param composer the key sequence to match
+     * @param callback the callback object to send possible word following previous word
+     * @param nextLettersFrequencies array of frequencies of next letters that could follow the
+     *        word so far. For instance, "bracke" can be followed by "t", so array['t'] will have
+     *        a non-zero value on returning from this method.
+     *        Pass in null if you don't want the dictionary to look up next letters.
+     */
+    public void getBigrams(final WordComposer composer, final CharSequence previousWord,
+            final WordCallback callback, int[] nextLettersFrequencies) {
+        // empty base implementation
+    }
+
+    /**
      * Checks if the given word occurs in the dictionary
      * @param word the word to search for. The search should be case-insensitive.
      * @return true if the word exists, false otherwise
diff --git a/java/src/com/android/inputmethod/latin/EditingUtil.java b/java/src/com/android/inputmethod/latin/EditingUtil.java
index 7571f1d..5133c60 100644
--- a/java/src/com/android/inputmethod/latin/EditingUtil.java
+++ b/java/src/com/android/inputmethod/latin/EditingUtil.java
@@ -16,6 +16,8 @@
 
 package com.android.inputmethod.latin;
 
+import java.util.regex.Pattern;
+
 import android.view.inputmethod.ExtractedText;
 import android.view.inputmethod.ExtractedTextRequest;
 import android.view.inputmethod.InputConnection;
@@ -24,6 +26,11 @@
  * Utility methods to deal with editing text through an InputConnection.
  */
 public class EditingUtil {
+    /**
+     * Number of characters we want to look back in order to identify the previous word
+     */
+    public static final int LOOKBACK_CHARACTER_NUM = 15;
+
     private EditingUtil() {};
 
     /**
@@ -175,4 +182,13 @@
     private static boolean isWhitespace(int code, String whitespace) {
         return whitespace.contains(String.valueOf((char) code));
     }
+
+    private static final Pattern spaceRegex = Pattern.compile("\\s+");
+
+    public static CharSequence getPreviousWord(InputConnection connection) {
+        //TODO: Should fix this. This could be slow!
+        CharSequence prev = connection.getTextBeforeCursor(LOOKBACK_CHARACTER_NUM, 0);
+        String[] w = spaceRegex.split(prev);
+        return (w.length >= 2) ? w[w.length-2] : null;
+    }
 }
diff --git a/java/src/com/android/inputmethod/latin/ExpandableDictionary.java b/java/src/com/android/inputmethod/latin/ExpandableDictionary.java
index 46bc41c..6f4d925 100644
--- a/java/src/com/android/inputmethod/latin/ExpandableDictionary.java
+++ b/java/src/com/android/inputmethod/latin/ExpandableDictionary.java
@@ -267,7 +267,7 @@
             if (completion) {
                 word[depth] = c;
                 if (terminal) {
-                    if (!callback.addWord(word, 0, depth + 1, freq * snr)) {
+                    if (!callback.addWord(word, 0, depth + 1, freq * snr, DataType.UNIGRAM)) {
                         return;
                     }
                     // Add to frequency of next letters for predictive correction
@@ -305,7 +305,8 @@
                                         || !same(word, depth + 1, codes.getTypedWord())) {
                                     int finalFreq = freq * snr * addedAttenuation;
                                     if (skipPos < 0) finalFreq *= FULL_WORD_FREQ_MULTIPLIER;
-                                    callback.addWord(word, 0, depth + 1, finalFreq);
+                                    callback.addWord(word, 0, depth + 1, finalFreq,
+                                            DataType.UNIGRAM);
                                 }
                             }
                             if (children != null) {
diff --git a/java/src/com/android/inputmethod/latin/LatinIME.java b/java/src/com/android/inputmethod/latin/LatinIME.java
index b1b6d92..51fb9d8 100644
--- a/java/src/com/android/inputmethod/latin/LatinIME.java
+++ b/java/src/com/android/inputmethod/latin/LatinIME.java
@@ -89,6 +89,7 @@
     private static final String PREF_QUICK_FIXES = "quick_fixes";
     private static final String PREF_SHOW_SUGGESTIONS = "show_suggestions";
     private static final String PREF_AUTO_COMPLETE = "auto_complete";
+    private static final String PREF_BIGRAM_SUGGESTIONS = "bigram_suggestion";
     private static final String PREF_VOICE_MODE = "voice_mode";
 
     // Whether or not the user has used voice input before (and thus, whether to show the
@@ -187,6 +188,7 @@
     private boolean mAutoSpace;
     private boolean mJustAddedAutoSpace;
     private boolean mAutoCorrectEnabled;
+    private boolean mBigramSuggestionEnabled;
     private boolean mAutoCorrectOn;
     private boolean mCapsLock;
     private boolean mPasswordText;
@@ -1538,7 +1540,7 @@
     }
 
     private List<CharSequence> getTypedSuggestions(WordComposer word) {
-        List<CharSequence> stringList = mSuggest.getSuggestions(mInputView, word, false);
+        List<CharSequence> stringList = mSuggest.getSuggestions(mInputView, word, false, null);
         return stringList;
     }
 
@@ -1549,7 +1551,14 @@
     }
 
     private void showSuggestions(WordComposer word) {
-        List<CharSequence> stringList = mSuggest.getSuggestions(mInputView, word, false);
+        //long startTime = System.currentTimeMillis(); // TIME MEASUREMENT!
+        // TODO Maybe need better way of retrieving previous word
+        CharSequence prevWord = EditingUtil.getPreviousWord(getCurrentInputConnection());
+        List<CharSequence> stringList = mSuggest.getSuggestions(mInputView, word, false,
+                prevWord);
+        //long stopTime = System.currentTimeMillis(); // TIME MEASUREMENT!
+        //Log.d("LatinIME","Suggest Total Time - " + (stopTime - startTime));
+
         int[] nextLettersFrequencies = mSuggest.getNextLettersFrequencies();
 
         ((LatinKeyboard) mInputView.getKeyboard()).setPreferredLetters(nextLettersFrequencies);
@@ -2088,6 +2097,8 @@
         mCorrectionMode = (mAutoCorrectOn && mAutoCorrectEnabled)
                 ? Suggest.CORRECTION_FULL
                 : (mAutoCorrectOn ? Suggest.CORRECTION_BASIC : Suggest.CORRECTION_NONE);
+        mCorrectionMode = (mBigramSuggestionEnabled && mAutoCorrectOn && mAutoCorrectEnabled)
+                ? Suggest.CORRECTION_FULL_BIGRAM : mCorrectionMode;
         if (mSuggest != null) {
             mSuggest.setCorrectionMode(mCorrectionMode);
         }
@@ -2154,6 +2165,7 @@
         }
         mAutoCorrectEnabled = sp.getBoolean(PREF_AUTO_COMPLETE,
                 mResources.getBoolean(R.bool.enable_autocorrect)) & mShowSuggestions;
+        mBigramSuggestionEnabled = sp.getBoolean(PREF_BIGRAM_SUGGESTIONS, true) & mShowSuggestions;
         updateCorrectionMode();
         updateAutoTextEnabled(mResources.getConfiguration().locale);
         mLanguageSwitcher.loadLocales(sp);
diff --git a/java/src/com/android/inputmethod/latin/Suggest.java b/java/src/com/android/inputmethod/latin/Suggest.java
index 010913d..3e6090c 100755
--- a/java/src/com/android/inputmethod/latin/Suggest.java
+++ b/java/src/com/android/inputmethod/latin/Suggest.java
@@ -37,6 +37,21 @@
     public static final int CORRECTION_NONE = 0;
     public static final int CORRECTION_BASIC = 1;
     public static final int CORRECTION_FULL = 2;
+    public static final int CORRECTION_FULL_BIGRAM = 3;
+
+    /**
+     * Words that appear in both bigram and unigram data gets multiplier ranging from
+     * BIGRAM_MULTIPLIER_MIN to BIGRAM_MULTIPLIER_MAX depending on the frequency score from
+     * bigram data.
+     */
+    public static final double BIGRAM_MULTIPLIER_MIN = 1.2;
+    public static final double BIGRAM_MULTIPLIER_MAX = 1.5;
+
+    /**
+     * Maximum possible bigram frequency. Will depend on how many bits are being used in data
+     * structure. Maximum bigram freqeuncy will get the BIGRAM_MULTIPLIER_MAX as the multiplier.
+     */
+    public static final int MAXIMUM_BIGRAM_FREQUENCY = 127;
 
     static final int LARGE_DICTIONARY_THRESHOLD = 200 * 1000;
 
@@ -49,10 +64,13 @@
     private Dictionary mContactsDictionary;
 
     private int mPrefMaxSuggestions = 12;
+    private int mPrefMaxBigrams = 255;
 
     private boolean mAutoTextEnabled;
 
     private int[] mPriorities = new int[mPrefMaxSuggestions];
+    private int[] mBigramPriorities = new int[mPrefMaxBigrams];
+
     // Handle predictive correction for only the first 1280 characters for performance reasons
     // If we support scripts that need latin characters beyond that, we should probably use some
     // kind of a sparse array or language specific list with a mapping lookup table.
@@ -60,6 +78,7 @@
     // latin characters.
     private int[] mNextLettersFrequencies = new int[1280];
     private ArrayList<CharSequence> mSuggestions = new ArrayList<CharSequence>();
+    private ArrayList<CharSequence> mBigramSuggestions  = new ArrayList<CharSequence>();
     private ArrayList<CharSequence> mStringPool = new ArrayList<CharSequence>();
     private boolean mHaveCorrection;
     private CharSequence mOriginalWord;
@@ -80,7 +99,7 @@
 
     private void initPool() {
         for (int i = 0; i < mPrefMaxSuggestions; i++) {
-            StringBuilder sb = new StringBuilder(32);
+            StringBuilder sb = new StringBuilder(Dictionary.MAX_WORD_LENGTH);
             mStringPool.add(sb);
         }
     }
@@ -132,9 +151,10 @@
         }
         mPrefMaxSuggestions = maxSuggestions;
         mPriorities = new int[mPrefMaxSuggestions];
-        collectGarbage();
+        mBigramPriorities = new int[mPrefMaxBigrams];
+        collectGarbage(mSuggestions, mPrefMaxSuggestions);
         while (mStringPool.size() < mPrefMaxSuggestions) {
-            StringBuilder sb = new StringBuilder(32);
+            StringBuilder sb = new StringBuilder(Dictionary.MAX_WORD_LENGTH);
             mStringPool.add(sb);
         }
     }
@@ -169,17 +189,16 @@
     /**
      * Returns a list of words that match the list of character codes passed in.
      * This list will be overwritten the next time this function is called.
-     * @param a view for retrieving the context for AutoText
-     * @param codes the list of codes. Each list item contains an array of character codes
-     * in order of probability where the character at index 0 in the array has the highest 
-     * probability. 
+     * @param view a view for retrieving the context for AutoText
+     * @param wordComposer contains what is currently being typed
+     * @param prevWordForBigram previous word (used only for bigram)
      * @return list of suggestions.
      */
     public List<CharSequence> getSuggestions(View view, WordComposer wordComposer, 
-            boolean includeTypedWordIfValid) {
+            boolean includeTypedWordIfValid, CharSequence prevWordForBigram) {
         mHaveCorrection = false;
         mCapitalize = wordComposer.isCapitalized();
-        collectGarbage();
+        collectGarbage(mSuggestions, mPrefMaxSuggestions);
         Arrays.fill(mPriorities, 0);
         Arrays.fill(mNextLettersFrequencies, 0);
 
@@ -191,8 +210,39 @@
         } else {
             mLowerOriginalWord = "";
         }
-        // Search the dictionary only if there are at least 2 characters
-        if (wordComposer.size() > 1) {
+
+        if (wordComposer.size() == 1 && (mCorrectionMode == CORRECTION_FULL_BIGRAM
+                || mCorrectionMode == CORRECTION_BASIC)) {
+            // At first character, just get the bigrams
+            Arrays.fill(mBigramPriorities, 0);
+            collectGarbage(mBigramSuggestions, mPrefMaxBigrams);
+
+            if (!TextUtils.isEmpty(prevWordForBigram)) {
+                CharSequence lowerPrevWord = prevWordForBigram.toString().toLowerCase();
+                if (mMainDict.isValidWord(lowerPrevWord)) {
+                    prevWordForBigram = lowerPrevWord;
+                }
+                mMainDict.getBigrams(wordComposer, prevWordForBigram, this,
+                        mNextLettersFrequencies);
+                char currentChar = wordComposer.getTypedWord().charAt(0);
+                int count = 0;
+                int bigramSuggestionSize = mBigramSuggestions.size();
+                for (int i = 0; i < bigramSuggestionSize; i++) {
+                    if (mBigramSuggestions.get(i).charAt(0) == currentChar) {
+                        int poolSize = mStringPool.size();
+                        StringBuilder sb = poolSize > 0 ?
+                                (StringBuilder) mStringPool.remove(poolSize - 1)
+                                : new StringBuilder(Dictionary.MAX_WORD_LENGTH);
+                        sb.setLength(0);
+                        sb.append(mBigramSuggestions.get(i));
+                        mSuggestions.add(count++, sb);
+                        if (count > mPrefMaxSuggestions) break;
+                    }
+                }
+            }
+
+        } else if (wordComposer.size() > 1) {
+            // Search the dictionary only if there are at least 2 characters
             if (mUserDictionary != null || mContactsDictionary != null) {
                 if (mUserDictionary != null) {
                     mUserDictionary.getWords(wordComposer, this, mNextLettersFrequencies);
@@ -202,21 +252,26 @@
                 }
 
                 if (mSuggestions.size() > 0 && isValidWord(mOriginalWord)
-                        && mCorrectionMode == CORRECTION_FULL) {
+                        && (mCorrectionMode == CORRECTION_FULL
+                        || mCorrectionMode == CORRECTION_FULL_BIGRAM)) {
                     mHaveCorrection = true;
                 }
             }
             mMainDict.getWords(wordComposer, this, mNextLettersFrequencies);
-            if (mCorrectionMode == CORRECTION_FULL && mSuggestions.size() > 0) {
+            if ((mCorrectionMode == CORRECTION_FULL || mCorrectionMode == CORRECTION_FULL_BIGRAM)
+                    && mSuggestions.size() > 0) {
                 mHaveCorrection = true;
             }
         }
+
         if (mOriginalWord != null) {
             mSuggestions.add(0, mOriginalWord.toString());
         }
-        
+
         // Check if the first suggestion has a minimum number of characters in common
-        if (mCorrectionMode == CORRECTION_FULL && mSuggestions.size() > 1) {
+        if (wordComposer.size() > 1 && mSuggestions.size() > 1
+                && (mCorrectionMode == CORRECTION_FULL
+                || mCorrectionMode == CORRECTION_FULL_BIGRAM)) {
             if (!haveSufficientCommonality(mLowerOriginalWord, mSuggestions.get(1))) {
                 mHaveCorrection = false;
             }
@@ -247,7 +302,6 @@
                 i++;
             }
         }
-
         removeDupes();
         return mSuggestions;
     }
@@ -301,20 +355,50 @@
         return false;
     }
 
-    public boolean addWord(final char[] word, final int offset, final int length, final int freq) {
+    public boolean addWord(final char[] word, final int offset, final int length, int freq,
+            final Dictionary.DataType dataType) {
+        ArrayList<CharSequence> suggestions;
+        int[] priorities;
+        int prefMaxSuggestions;
+        if(dataType == Dictionary.DataType.BIGRAM) {
+            suggestions = mBigramSuggestions;
+            priorities = mBigramPriorities;
+            prefMaxSuggestions = mPrefMaxBigrams;
+        } else {
+            suggestions = mSuggestions;
+            priorities = mPriorities;
+            prefMaxSuggestions = mPrefMaxSuggestions;
+        }
+
         int pos = 0;
-        final int[] priorities = mPriorities;
-        final int prefMaxSuggestions = mPrefMaxSuggestions;
+
         // Check if it's the same word, only caps are different
         if (compareCaseInsensitive(mLowerOriginalWord, word, offset, length)) {
             pos = 0;
         } else {
+            if (dataType == Dictionary.DataType.UNIGRAM) {
+                // Check if the word was already added before (by bigram data)
+                int bigramSuggestion = searchBigramSuggestion(word,offset,length);
+                if(bigramSuggestion >= 0) {
+                    // turn freq from bigram into multiplier specified above
+                    double multiplier = (((double) mBigramPriorities[bigramSuggestion])
+                            / MAXIMUM_BIGRAM_FREQUENCY)
+                            * (BIGRAM_MULTIPLIER_MAX - BIGRAM_MULTIPLIER_MIN)
+                            + BIGRAM_MULTIPLIER_MIN;
+                    /* Log.d("Suggest","bigram num: " + bigramSuggestion
+                            + "  wordB: " + mBigramSuggestions.get(bigramSuggestion).toString()
+                            + "  currentPriority: " + freq + "  bigramPriority: "
+                            + mBigramPriorities[bigramSuggestion]
+                            + "  multiplier: " + multiplier); */
+                    freq = (int)Math.round((freq * multiplier));
+                }
+            }
+
             // Check the last one's priority and bail
             if (priorities[prefMaxSuggestions - 1] >= freq) return true;
             while (pos < prefMaxSuggestions) {
                 if (priorities[pos] < freq
-                        || (priorities[pos] == freq && length < mSuggestions
-                                .get(pos).length())) {
+                        || (priorities[pos] == freq && length < suggestions.get(pos).length())) {
                     break;
                 }
                 pos++;
@@ -324,12 +408,13 @@
         if (pos >= prefMaxSuggestions) {
             return true;
         }
+
         System.arraycopy(priorities, pos, priorities, pos + 1,
                 prefMaxSuggestions - pos - 1);
         priorities[pos] = freq;
         int poolSize = mStringPool.size();
         StringBuilder sb = poolSize > 0 ? (StringBuilder) mStringPool.remove(poolSize - 1) 
-                : new StringBuilder(32);
+                : new StringBuilder(Dictionary.MAX_WORD_LENGTH);
         sb.setLength(0);
         if (mCapitalize) {
             sb.append(Character.toUpperCase(word[offset]));
@@ -339,9 +424,9 @@
         } else {
             sb.append(word, offset, length);
         }
-        mSuggestions.add(pos, sb);
-        if (mSuggestions.size() > prefMaxSuggestions) {
-            CharSequence garbage = mSuggestions.remove(prefMaxSuggestions);
+        suggestions.add(pos, sb);
+        if (suggestions.size() > prefMaxSuggestions) {
+            CharSequence garbage = suggestions.remove(prefMaxSuggestions);
             if (garbage instanceof StringBuilder) {
                 mStringPool.add(garbage);
             }
@@ -349,6 +434,26 @@
         return true;
     }
 
+    private int searchBigramSuggestion(final char[] word, final int offset, final int length) {
+        // TODO This is almost O(n^2). Might need fix.
+        // search whether the word appeared in bigram data
+        int bigramSuggestSize = mBigramSuggestions.size();
+        for(int i = 0; i < bigramSuggestSize; i++) {
+            if(mBigramSuggestions.get(i).length() == length) {
+                boolean chk = true;
+                for(int j = 0; j < length; j++) {
+                    if(mBigramSuggestions.get(i).charAt(j) != word[offset+j]) {
+                        chk = false;
+                        break;
+                    }
+                }
+                if(chk) return i;
+            }
+        }
+
+        return -1;
+    }
+
     public boolean isValidWord(final CharSequence word) {
         if (word == null || word.length() == 0) {
             return false;
@@ -359,21 +464,21 @@
                 || (mContactsDictionary != null && mContactsDictionary.isValidWord(word));
     }
     
-    private void collectGarbage() {
+    private void collectGarbage(ArrayList<CharSequence> suggestions, int prefMaxSuggestions) {
         int poolSize = mStringPool.size();
-        int garbageSize = mSuggestions.size();
-        while (poolSize < mPrefMaxSuggestions && garbageSize > 0) {
-            CharSequence garbage = mSuggestions.get(garbageSize - 1);
+        int garbageSize = suggestions.size();
+        while (poolSize < prefMaxSuggestions && garbageSize > 0) {
+            CharSequence garbage = suggestions.get(garbageSize - 1);
             if (garbage != null && garbage instanceof StringBuilder) {
                 mStringPool.add(garbage);
                 poolSize++;
             }
             garbageSize--;
         }
-        if (poolSize == mPrefMaxSuggestions + 1) {
+        if (poolSize == prefMaxSuggestions + 1) {
             Log.w("Suggest", "String pool got too big: " + poolSize);
         }
-        mSuggestions.clear();
+        suggestions.clear();
     }
 
     public void close() {