diff --git a/src/alloc.c b/src/alloc.c
index 84a1124..20df46c 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -236,7 +236,7 @@
     // if some blocks are released call malloc again.
     for (;;)
     {
-	// Handle three kind of systems:
+	// Handle three kinds of systems:
 	// 1. No check for available memory: Just return.
 	// 2. Slow check for available memory: call mch_avail_mem() after
 	//    allocating KEEP_ROOM amount of memory.
diff --git a/src/blowfish.c b/src/blowfish.c
index 4502a1c..4f6ce01 100644
--- a/src/blowfish.c
+++ b/src/blowfish.c
@@ -651,7 +651,7 @@
     state->method_state = bfs;
 
     // "blowfish" uses a 64 byte buffer, causing it to repeat 8 byte groups 8
-    // times.  "blowfish2" uses a 8 byte buffer to avoid repeating.
+    // times.  "blowfish2" uses an 8 byte buffer to avoid repeating.
     bfs->cfb_len = state->method_nr == CRYPT_M_BF ? BF_MAX_CFB_LEN : BF_BLOCK;
 
     if (blowfish_self_test() == FAIL)
diff --git a/src/buffer.c b/src/buffer.c
index cbb57ef..5e41e64 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -1823,7 +1823,7 @@
     if (curbuf->b_ml.ml_mfp == NULL)	// need to load the file
     {
 	// If there is no filetype, allow for detecting one.  Esp. useful for
-	// ":ball" used in a autocommand.  If there already is a filetype we
+	// ":ball" used in an autocommand.  If there already is a filetype we
 	// might prefer to keep it.
 	if (*curbuf->b_p_ft == NUL)
 	    did_filetype = FALSE;
@@ -5031,7 +5031,7 @@
 	sp->userhl = 0;
     }
 
-    // When inside update_screen we do not want redrawing a stausline, ruler,
+    // When inside update_screen we do not want redrawing a statusline, ruler,
     // title, etc. to trigger another redraw, it may cause an endless loop.
     if (updating_screen)
     {
diff --git a/src/cindent.c b/src/cindent.c
index 42b46e4..9f1db03 100644
--- a/src/cindent.c
+++ b/src/cindent.c
@@ -1223,7 +1223,7 @@
 	if (*s == ')' && cin_nocode(s + 1))
 	{
 	    // ')' at the end: may have found a match
-	    // Check for he previous line not to end in a backslash:
+	    // Check for the previous line not to end in a backslash:
 	    //       #if defined(x) && {backslash}
 	    //		 defined(y)
 	    lnum = first_lnum - 1;
@@ -1792,7 +1792,7 @@
     buf->b_ind_unclosed2 = sw;
 
     // Suppress ignoring spaces from the indent of a line starting with an
-    // unclosed parentheses.
+    // unclosed parenthesis.
     buf->b_ind_unclosed_noignore = 0;
 
     // If the opening paren is the last nonwhite character on the line, and
@@ -1804,11 +1804,11 @@
     // an unclosed parenthesis.
     buf->b_ind_unclosed_whiteok = 0;
 
-    // Indent a closing parentheses under the line start of the matching
-    // opening parentheses.
+    // Indent a closing parenthesis under the line start of the matching
+    // opening parenthesis.
     buf->b_ind_matching_paren = 0;
 
-    // Indent a closing parentheses under the previous line.
+    // Indent a closing parenthesis under the previous line.
     buf->b_ind_paren_prev = 0;
 
     // Extra indent for comments.
diff --git a/src/clipboard.c b/src/clipboard.c
index c0c21ae..38596f5 100644
--- a/src/clipboard.c
+++ b/src/clipboard.c
@@ -567,7 +567,7 @@
 	return;
 
     p = ScreenLines + LineOffset[row];
-    // Correct for starting in the right halve of a double-wide char
+    // Correct for starting in the right half of a double-wide char
     if (enc_dbcs != 0)
 	col -= dbcs_screen_head_off(p, p + col);
     else if (enc_utf8 && p[col] == 0)
@@ -1030,7 +1030,7 @@
     if (row2 > clip_star.max_row)
 	row2 = clip_star.max_row;
 #endif
-    // correct starting point for being on right halve of double-wide char
+    // correct starting point for being on right half of double-wide char
     p = ScreenLines + LineOffset[row1];
     if (enc_dbcs != 0)
 	col1 -= (*mb_head_off)(p, p + col1);
@@ -1140,7 +1140,7 @@
 									bufp);
 			}
 		    }
-		    // Skip right halve of double-wide character.
+		    // Skip right half of double-wide character.
 		    if (ScreenLines[off + i + 1] == 0)
 			++i;
 		}
diff --git a/src/diff.c b/src/diff.c
index 45c5e0b..e9367b5 100644
--- a/src/diff.c
+++ b/src/diff.c
@@ -693,11 +693,11 @@
     if (wp_other != NULL && curwin->w_p_scb)
     {
 	if (used_max_fill_curwin)
-	    // The current window was set to used the maximum number of filler
+	    // The current window was set to use the maximum number of filler
 	    // lines, may need to reduce them.
 	    diff_set_topline(wp_other, curwin);
 	else if (used_max_fill_other)
-	    // The other window was set to used the maximum number of filler
+	    // The other window was set to use the maximum number of filler
 	    // lines, may need to reduce them.
 	    diff_set_topline(curwin, wp_other);
     }
@@ -1595,7 +1595,7 @@
 	diff_clear(curtab);
     }
 
-    // Remove "hor" from from 'scrollopt' if there are no diff windows left.
+    // Remove "hor" from 'scrollopt' if there are no diff windows left.
     if (!diffwin && vim_strchr(p_sbo, 'h') != NULL)
 	do_cmdline_cmd((char_u *)"set sbo-=hor");
 }
diff --git a/src/drawline.c b/src/drawline.c
index 7125b80..8a042ed 100644
--- a/src/drawline.c
+++ b/src/drawline.c
@@ -2258,7 +2258,7 @@
 
 			// Make sure, the highlighting for the tab char will be
 			// correctly set further below (effectively reverts the
-			// FIX_FOR_BOGSUCOLS macro
+			// FIX_FOR_BOGSUCOLS macro).
 			if (n_extra == tab_len + vc_saved && wp->w_p_list
 						&& wp->w_lcs_chars.tab1)
 			    tab_len += vc_saved;
@@ -2938,7 +2938,7 @@
 #if defined(FEAT_RIGHTLEFT)
 	    if (has_mbyte && wp->w_p_rl && (*mb_char2cells)(mb_c) > 1)
 	    {
-		// A double-wide character is: put first halve in left cell.
+		// A double-wide character is: put first half in left cell.
 		--off;
 		--col;
 	    }
diff --git a/src/edit.c b/src/edit.c
index 9ff1c18..f4e9327 100644
--- a/src/edit.c
+++ b/src/edit.c
@@ -1657,8 +1657,8 @@
  */
 static int  pc_status;
 #define PC_STATUS_UNSET	0	// pc_bytes was not set
-#define PC_STATUS_RIGHT	1	// right halve of double-wide char
-#define PC_STATUS_LEFT	2	// left halve of double-wide char
+#define PC_STATUS_RIGHT	1	// right half of double-wide char
+#define PC_STATUS_LEFT	2	// left half of double-wide char
 #define PC_STATUS_SET	3	// pc_bytes was filled
 static char_u pc_bytes[MB_MAXBYTES + 1]; // saved bytes
 static int  pc_attr;
diff --git a/src/ex_cmds.c b/src/ex_cmds.c
index ff978ad..8595e8b 100644
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -3378,7 +3378,7 @@
     // "start" is set to eap->line2+1 unless that position is invalid (when
     // eap->line2 pointed to the end of the buffer and nothing was appended)
     // "end" is set to lnum when something has been appended, otherwise
-    // it is the same than "start"  -- Acevedo
+    // it is the same as "start"  -- Acevedo
     if ((cmdmod.cmod_flags & CMOD_LOCKMARKS) == 0)
     {
 	curbuf->b_op_start.lnum = (eap->line2 < curbuf->b_ml.ml_line_count) ?
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index ab0a146f..20b2457 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -3744,7 +3744,7 @@
 		break;
 	    }
 
-	// Not not recognize ":*" as the star command unless '*' is in
+	// Do not recognize ":*" as the star command unless '*' is in
 	// 'cpoptions'.
 	if (eap->cmdidx == CMD_star && vim_strchr(p_cpo, CPO_STAR) == NULL)
 	    p = eap->cmd;
@@ -6977,7 +6977,7 @@
 		|| eap->cmdidx == CMD_tabedit
 		|| eap->cmdidx == CMD_vnew) && *eap->arg == NUL)
     {
-	// ":new" or ":tabnew" without argument: edit an new empty buffer
+	// ":new" or ":tabnew" without argument: edit a new empty buffer
 	setpcmark();
 	(void)do_ecmd(0, NULL, NULL, eap, ECMD_ONE,
 		      ECMD_HIDE + (eap->forceit ? ECMD_FORCEIT : 0),
diff --git a/src/findfile.c b/src/findfile.c
index ab59776..d3de9fc 100644
--- a/src/findfile.c
+++ b/src/findfile.c
@@ -749,7 +749,7 @@
 	// downward search loop
 	for (;;)
 	{
-	    // check if user user wants to stop the search
+	    // check if user wants to stop the search
 	    ui_breakcheck();
 	    if (got_int)
 		break;
@@ -1376,7 +1376,7 @@
     int			url = FALSE;
 #endif
 
-    // For an URL we only compare the name, otherwise we compare the
+    // For a URL we only compare the name, otherwise we compare the
     // device/inode (unix) or the full path name (not Unix).
     if (path_with_url(fname))
     {
diff --git a/src/fold.c b/src/fold.c
index d4a6267..7d993f7 100644
--- a/src/fold.c
+++ b/src/fold.c
@@ -2513,7 +2513,7 @@
 	     */
 	    while (!got_int)
 	    {
-		// set concat to 1 if it's allowed to concatenated this fold
+		// set concat to 1 if it's allowed to concatenate this fold
 		// with a previous one that touches it.
 		if (flp->start != 0 || flp->had_end <= MAX_LEVEL)
 		    concat = 0;
diff --git a/src/getchar.c b/src/getchar.c
index c357354..102eb2f 100644
--- a/src/getchar.c
+++ b/src/getchar.c
@@ -76,7 +76,7 @@
 
 // typebuf.tb_buf has three parts: room in front (for result of mappings), the
 // middle for typeahead and room for new characters (which needs to be 3 *
-// MAXMAPLEN) for the Amiga).
+// MAXMAPLEN for the Amiga).
 #define TYPELEN_INIT	(5 * (MAXMAPLEN + 3))
 static char_u	typebuf_init[TYPELEN_INIT];	// initial typebuf.tb_buf
 static char_u	noremapbuf_init[TYPELEN_INIT];	// initial typebuf.tb_noremap
@@ -941,7 +941,7 @@
  *
  * If noremap is REMAP_YES, new string can be mapped again.
  * If noremap is REMAP_NONE, new string cannot be mapped again.
- * If noremap is REMAP_SKIP, fist char of new string cannot be mapped again,
+ * If noremap is REMAP_SKIP, first char of new string cannot be mapped again,
  * but abbreviations are allowed.
  * If noremap is REMAP_SCRIPT, new string cannot be mapped again, except for
  *			script-local mappings.
@@ -3457,7 +3457,7 @@
 inchar(
     char_u	*buf,
     int		maxlen,
-    long	wait_time)	    // milli seconds
+    long	wait_time)	    // milliseconds
 {
     int		len = 0;	    // init for GCC
     int		retesc = FALSE;	    // return ESC with gotint
diff --git a/src/gui.c b/src/gui.c
index 74d681e..9b19cef 100644
--- a/src/gui.c
+++ b/src/gui.c
@@ -490,7 +490,7 @@
     static int	recursive = 0;
 
     /*
-     * It's possible to use ":gui" in a .gvimrc file.  The first halve of this
+     * It's possible to use ":gui" in a .gvimrc file.  The first half of this
      * function will then be executed at the first call, the rest by the
      * recursive call.  This allow the shell to be opened halfway reading a
      * gvimrc file.
@@ -1371,10 +1371,10 @@
 #ifdef FEAT_RIGHTLEFT
 		if (CURSOR_BAR_RIGHT)
 		{
-		    // gui.col points to the left halve of the character but
-		    // the vertical line needs to be on the right halve.
+		    // gui.col points to the left half of the character but
+		    // the vertical line needs to be on the right half.
 		    // A double-wide horizontal line is also drawn from the
-		    // right halve in gui_mch_draw_part_cursor().
+		    // right half in gui_mch_draw_part_cursor().
 		    col_off = TRUE;
 		    ++gui.col;
 		}
@@ -2188,7 +2188,7 @@
 {
     char_u	buf[MB_MAXBYTES + 1];
 
-    // Don't draw right halve of a double-width UTF-8 char. "cannot happen"
+    // Don't draw right half of a double-width UTF-8 char. "cannot happen"
     if (enc_utf8 && ScreenLines[off] == 0)
 	return OK;
 
@@ -3074,7 +3074,7 @@
 gui_inchar(
     char_u  *buf,
     int	    maxlen,
-    long    wtime,		// milli seconds
+    long    wtime,		// milliseconds
     int	    tb_change_cnt)
 {
     return gui_wait_for_chars_buf(buf, maxlen, wtime, tb_change_cnt);
@@ -3277,7 +3277,7 @@
      * selection.  But if Visual is active, assume that only the Visual area
      * will be selected.
      * Exception: On the command line, both the selection is used and a mouse
-     * key is send.
+     * key is sent.
      */
     if (!mouse_has(checkfor) || checkfor == MOUSE_COMMAND)
     {
@@ -5376,7 +5376,7 @@
 
     // When the screen is being updated we should not change buffers and
     // windows structures, it may cause freed memory to be used.  Also don't
-    // do this recursively (pressing "Find" quickly several times.
+    // do this recursively (pressing "Find" quickly several times).
     if (updating_screen || busy)
 	return FALSE;
 
diff --git a/src/gui_athena.c b/src/gui_athena.c
index f4aafcd..4da832b 100644
--- a/src/gui_athena.c
+++ b/src/gui_athena.c
@@ -216,7 +216,7 @@
     else if (value < 0)
 	value = 0;
 
-    // Update the bottom scrollbar an extra time (why is this needed??
+    // Update the bottom scrollbar an extra time (why is this needed??)
     if (sb->wp == NULL)		// Bottom scrollbar
 	gui_mch_set_scrollbar_thumb(sb, value, sb->size, sb->max);
 
diff --git a/src/gui_gtk.c b/src/gui_gtk.c
index 2ea7a5e..08290a5 100644
--- a/src/gui_gtk.c
+++ b/src/gui_gtk.c
@@ -2242,7 +2242,7 @@
 	gtk_window_present(GTK_WINDOW(frdp->dialog));
 
 	// For :promptfind dialog, always give keyboard focus to 'what' entry.
-	// For :promptrepl dialog, give it to 'with' entry if 'what' has an
+	// For :promptrepl dialog, give it to 'with' entry if 'what' has a
 	// non-empty entry; otherwise, to 'what' entry.
 	gtk_widget_grab_focus(frdp->what);
 	if (do_replace && entry_get_text_length(GTK_ENTRY(frdp->what)) > 0)
diff --git a/src/gui_motif.c b/src/gui_motif.c
index d79a414..1d95651 100644
--- a/src/gui_motif.c
+++ b/src/gui_motif.c
@@ -2768,7 +2768,7 @@
     // Create the dialog message.
     // Since LessTif is apparently having problems with the creation of
     // properly localized string, we use LtoR here. The symptom is that the
-    // string sill not show properly in multiple lines as it does in native
+    // string is not shown properly in multiple lines as it does in native
     // Motif.
     label = XmStringCreateLtoR((char *)message, STRING_TAG);
     if (label == NULL)
diff --git a/src/gui_photon.c b/src/gui_photon.c
index c89d781..ea8e5e4 100644
--- a/src/gui_photon.c
+++ b/src/gui_photon.c
@@ -487,7 +487,7 @@
 		    if (key->key_cap >= Pk_KP_Enter && key->key_cap <= Pk_KP_9
 			    && (key->key_mods & Pk_KM_Num_Lock))
 		    {
-			// FIXME: For now, just map the key to a ascii value
+			// FIXME: For now, just map the key to an ascii value
 			// (see <photon/PkKeyDef.h>)
 			ch = key->key_cap - 0xf080;
 		    }
diff --git a/src/gui_w32.c b/src/gui_w32.c
index b879aa3..4edce2e 100644
--- a/src/gui_w32.c
+++ b/src/gui_w32.c
@@ -3041,7 +3041,7 @@
     if (!is_window_onscreen(s_hwnd))
 	return SW_INVALIDATE;
 
-    // Check if there is an window (partly) on top of us.
+    // Check if there is a window (partly) on top of us.
     GetWindowRect(s_hwnd, &rcVim);
     for (hwnd = s_hwnd; (hwnd = GetWindow(hwnd, GW_HWNDPREV)) != (HWND)0; )
 	if (IsWindowVisible(hwnd))
@@ -5740,7 +5740,7 @@
     if (!pImmGetContext)
 	return NULL; // no imm32.dll
 
-    // Try Unicode; this'll always work on NT regardless of codepage.
+    // Try Unicode; this will always work on NT regardless of codepage.
     ret = pImmGetCompositionStringW(hIMC, GCS, NULL, 0);
     if (ret == 0)
 	return NULL; // empty
@@ -5757,7 +5757,7 @@
 	return (short_u *)wbuf;
     }
 
-    // ret < 0; we got an error, so try the ANSI version.  This'll work
+    // ret < 0; we got an error, so try the ANSI version.  This will work
     // on 9x/ME, but only if the codepage happens to be set to whatever
     // we're inputting.
     ret = pImmGetCompositionStringA(hIMC, GCS, NULL, 0);
@@ -7390,8 +7390,8 @@
 
     *p++ = 0;  // advance pointer over nExtraStuff WORD   - 2 more
 
-    return p;	//total = 15+ (strlen(caption)) words
-		//	   = 30 + 2(strlen(caption) bytes reqd
+    return p;	// total = 15 + strlen(caption) words
+		// bytes read = 2 * total
 }
 
 
diff --git a/src/gui_xmebw.c b/src/gui_xmebw.c
index 3387fbe..7ffa6f3 100644
--- a/src/gui_xmebw.c
+++ b/src/gui_xmebw.c
@@ -970,7 +970,7 @@
     }
     else
     {
-	// FIXME: We should calculate an drawing offset for the pixmap here to
+	// FIXME: We should calculate a drawing offset for the pixmap here to
 	// adjust it.
     }
 
diff --git a/src/if_python.c b/src/if_python.c
index a270982..1b7ff76 100644
--- a/src/if_python.c
+++ b/src/if_python.c
@@ -674,7 +674,7 @@
 
 # if !(defined(PY_NO_RTLD_GLOBAL) && defined(PY3_NO_RTLD_GLOBAL)) && defined(UNIX) && defined(FEAT_PYTHON3)
     // Can't have Python and Python3 loaded at the same time.
-    // It cause a crash, because RTLD_GLOBAL is needed for
+    // It causes a crash, because RTLD_GLOBAL is needed for
     // standard C extension libraries of one or both python versions.
     if (python3_loaded())
     {
@@ -1461,7 +1461,7 @@
     PyInt len = strlen(str);
     char *p;
 
-    // Allocate an Python string object, with uninitialised contents. We
+    // Allocate a Python string object, with uninitialised contents. We
     // must do it this way, so that we can modify the string in place
     // later. See the Python source, Objects/stringobject.c for details.
     result = PyString_FromStringAndSize(NULL, len);
diff --git a/src/if_python3.c b/src/if_python3.c
index 4944ab8..db88527 100644
--- a/src/if_python3.c
+++ b/src/if_python3.c
@@ -766,7 +766,7 @@
 
 # if !(defined(PY_NO_RTLD_GLOBAL) && defined(PY3_NO_RTLD_GLOBAL)) && defined(UNIX) && defined(FEAT_PYTHON)
     // Can't have Python and Python3 loaded at the same time.
-    // It cause a crash, because RTLD_GLOBAL is needed for
+    // It causes a crash, because RTLD_GLOBAL is needed for
     // standard C extension libraries of one or both python versions.
     if (python_loaded())
     {
diff --git a/src/if_xcmdsrv.c b/src/if_xcmdsrv.c
index 901afc4..c814f21 100644
--- a/src/if_xcmdsrv.c
+++ b/src/if_xcmdsrv.c
@@ -345,7 +345,7 @@
     DeleteAnyLingerer(dpy, newwin);
     if (serverName != NULL)
     {
-	// Reinsert name if we was already registered
+	// Reinsert name if it was already registered
 	(void)LookupName(dpy, serverName, /*delete=*/TRUE, NULL);
 	sprintf((char *)propInfo, "%x %.*s",
 		(int_u)newwin, MAX_NAME_LENGTH, serverName);
diff --git a/src/main.c b/src/main.c
index 6943c2f..5332249 100644
--- a/src/main.c
+++ b/src/main.c
@@ -247,7 +247,7 @@
 		mch_dirname(start_dir, MAXPATHL);
 	    // Temporarily add '(' and ')' to 'isfname'.  These are valid
 	    // filename characters but are excluded from 'isfname' to make
-	    // "gf" work on a file name in parenthesis (e.g.: see vim.h).
+	    // "gf" work on a file name in parentheses (e.g.: see vim.h).
 	    do_cmdline_cmd((char_u *)":set isf+=(,)");
 	    alist_expand(NULL, 0);
 	    do_cmdline_cmd((char_u *)":set isf&");
diff --git a/src/memline.c b/src/memline.c
index 119861e..a072746 100644
--- a/src/memline.c
+++ b/src/memline.c
@@ -4718,7 +4718,7 @@
      * MSDOS compatible filesystem, it is possible that the file
      * "test.doc.swp" which we create will be exactly the same file. To avoid
      * this problem we temporarily create "test.doc".  Don't do this when the
-     * check below for a 8.3 file name is used.
+     * check below for an 8.3 file name is used.
      */
     if (!(buf->b_p_sn || buf->b_shortname) && buf_fname != NULL
 					     && mch_getperm(buf_fname) < 0)
diff --git a/src/menu.c b/src/menu.c
index 2cd3270..c0a1f3a 100644
--- a/src/menu.c
+++ b/src/menu.c
@@ -582,7 +582,7 @@
 		goto erret;
 	    }
 
-	    // Not already there, so lets add it
+	    // Not already there, so let's add it
 	    menu = ALLOC_CLEAR_ONE(vimmenu_T);
 	    if (menu == NULL)
 		goto erret;
@@ -997,7 +997,7 @@
 	// Recalculate modes for menu based on the new updated children
 	menu->modes &= ~modes;
 #if defined(FEAT_GUI_MSWIN) & defined(FEAT_TEAROFF)
-	if ((s_tearoffs) && (menu->children != NULL)) // there's a tear bar..
+	if ((s_tearoffs) && (menu->children != NULL)) // there's a tear bar.
 	    child = menu->children->next; // don't count tearoff bar
 	else
 #endif
@@ -1018,7 +1018,7 @@
 	{
 	    // The menu item is no longer valid in ANY mode, so delete it
 #if defined(FEAT_GUI_MSWIN) & defined(FEAT_TEAROFF)
-	    if (s_tearoffs && menu->children != NULL) // there's a tear bar..
+	    if (s_tearoffs && menu->children != NULL) // there's a tear bar.
 		free_menu(&menu->children);
 #endif
 	    *menup = menu;
diff --git a/src/message.c b/src/message.c
index 8992de0..7e98d0b 100644
--- a/src/message.c
+++ b/src/message.c
@@ -1363,7 +1363,7 @@
 {
     int		save_p_more = p_more;
 
-    p_more = FALSE;	// don't want see this message when scrolling back
+    p_more = FALSE;	// don't want to see this message when scrolling back
     if (msg_didout)	// start on a new line
 	msg_putchar('\n');
     if (got_int)
diff --git a/src/misc1.c b/src/misc1.c
index ad26ab3..a8bc08e 100644
--- a/src/misc1.c
+++ b/src/misc1.c
@@ -371,7 +371,7 @@
 	return 1;
 
 #ifdef FEAT_FOLDING
-    // A folded lines is handled just like an empty line.
+    // Folded lines are handled just like an empty line.
     // NOTE: Caller must handle lines that are MAYBE folded.
     if (lineFolded(wp, lnum) == TRUE)
 	return 1;
diff --git a/src/move.c b/src/move.c
index 64b1296..b8e8780 100644
--- a/src/move.c
+++ b/src/move.c
@@ -1152,7 +1152,7 @@
 	}
 	else if (extra == 1)
 	{
-	    // less then 'scrolloff' lines above, decrease skipcol
+	    // less than 'scrolloff' lines above, decrease skipcol
 	    extra = (curwin->w_skipcol + so * width - curwin->w_virtcol
 				     + width - 1) / width;
 	    if (extra > 0)
@@ -1164,7 +1164,7 @@
 	}
 	else if (extra == 2)
 	{
-	    // less then 'scrolloff' lines below, increase skipcol
+	    // less than 'scrolloff' lines below, increase skipcol
 	    endcol = (n - curwin->w_height + 1) * width;
 	    while (endcol > curwin->w_virtcol)
 		endcol -= width;
diff --git a/src/option.c b/src/option.c
index 739b29a..9d596e4 100644
--- a/src/option.c
+++ b/src/option.c
@@ -1774,7 +1774,7 @@
 			    else if ((char_u **)varp == &p_fencs && enc_utf8)
 				newval = fencs_utf8_default;
 
-			    // expand environment variables and ~ (since the
+			    // expand environment variables and ~ since the
 			    // default value was already expanded, only
 			    // required when an environment variable was set
 			    // later
@@ -3139,7 +3139,7 @@
 		}
 	    }
 
-	    // Arabic requires a utf-8 encoding, inform the user if its not
+	    // Arabic requires a utf-8 encoding, inform the user if it's not
 	    // set.
 	    if (STRCMP(p_enc, "utf-8") != 0)
 	    {
diff --git a/src/os_amiga.c b/src/os_amiga.c
index 18f0192..5bf088b 100644
--- a/src/os_amiga.c
+++ b/src/os_amiga.c
@@ -153,7 +153,7 @@
 mch_inchar(
     char_u  *buf,
     int	    maxlen,
-    long    time,		// milli seconds
+    long    time,		// milliseconds
     int	    tb_change_cnt)
 {
     int	    len;
diff --git a/src/os_mac.h b/src/os_mac.h
index 6524609..dbc0086 100644
--- a/src/os_mac.h
+++ b/src/os_mac.h
@@ -7,7 +7,7 @@
  */
 
 // Before Including the MacOS specific files,
-// lets set the OPAQUE_TOOLBOX_STRUCTS to 0 so we
+// let's set the OPAQUE_TOOLBOX_STRUCTS to 0 so we
 // can access the internal structures.
 // (Until fully Carbon compliant)
 // TODO: Can we remove this? (Dany)
diff --git a/src/os_mac_conv.c b/src/os_mac_conv.c
index 734f8f6..211b235 100644
--- a/src/os_mac_conv.c
+++ b/src/os_mac_conv.c
@@ -258,7 +258,7 @@
 		kCFStringEncodingMacRoman,
 		0, // no lossy conversion
 		0, // not external representation (since vim
-		   // handles this internally
+		   // handles this internally)
 		to, maxtolen, &l))
     {
 	CFRelease(cfstr);
diff --git a/src/os_mswin.c b/src/os_mswin.c
index b6393db..26042b4 100644
--- a/src/os_mswin.c
+++ b/src/os_mswin.c
@@ -1907,7 +1907,7 @@
 # define VIM_CLASSNAME      "VIM_MESSAGES"
 # define VIM_CLASSNAME_LEN  (sizeof(VIM_CLASSNAME) - 1)
 
-// Communication is via WM_COPYDATA messages. The message type is send in
+// Communication is via WM_COPYDATA messages. The message type is sent in
 // the dwData parameter. Types are defined here.
 # define COPYDATA_KEYS		0
 # define COPYDATA_REPLY		1
@@ -2375,7 +2375,7 @@
 	return sendToLocalVim(cmd, asExpr, result);
 
     // If the server name does not end in a digit then we look for an
-    // alternate name.  e.g. when "name" is GVIM the we may find GVIM2.
+    // alternate name.  e.g. when "name" is GVIM then we may find GVIM2.
     if (STRLEN(name) > 1 && !vim_isdigit(name[STRLEN(name) - 1]))
 	altname_buf_ptr = altname_buf;
     altname_buf[0] = NUL;
diff --git a/src/os_unix.c b/src/os_unix.c
index 1c00f22..77f35db 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -3165,7 +3165,7 @@
     // Therefore, this check does not have any sense - let keep us to the
     // conventions instead:
     // *.COM and *.EXE files are the executables - the rest are not. This is
-    // not ideal but better then it was.
+    // not ideal but better than it was.
     int vms_executable = 0;
     if (S_ISREG(st.st_mode) && mch_access((char *)name, X_OK) == 0)
     {
diff --git a/src/os_win32.c b/src/os_win32.c
index 7234fe8..b0ff1bb 100644
--- a/src/os_win32.c
+++ b/src/os_win32.c
@@ -2187,7 +2187,7 @@
 	}
     }
 
-    // Prepend single "." to pathext, it's means no extension added.
+    // Prepend single "." to pathext, it means no extension added.
     if (pathext == NULL)
 	pathext = (char_u *)".";
     else if (noext == TRUE)
@@ -7750,7 +7750,7 @@
 	// Now expand wildcards in the arguments.
 	// Temporarily add '(' and ')' to 'isfname'.  These are valid
 	// filename characters but are excluded from 'isfname' to make
-	// "gf" work on a file name in parenthesis (e.g.: see vim.h).
+	// "gf" work on a file name in parentheses (e.g.: see vim.h).
 	// Also, unset wildignore to not be influenced by this option.
 	// The arguments specified in command-line should be kept even if
 	// encoding options were changed.
diff --git a/src/os_win32.h b/src/os_win32.h
index abe95b5..32e29ef 100644
--- a/src/os_win32.h
+++ b/src/os_win32.h
@@ -71,7 +71,7 @@
 #define HAVE_PUTENV		// at least Bcc 5.2 and MSC have it
 
 #if defined(FEAT_GUI_MSWIN) && !defined(VIMDLL)
-# define NO_CONSOLE		// don't included console-only code
+# define NO_CONSOLE		// don't include console-only code
 #endif
 
 // toupper() is not really broken, but it's very slow.	Probably because of
diff --git a/src/quickfix.c b/src/quickfix.c
index d0f4199..c007a9c 100644
--- a/src/quickfix.c
+++ b/src/quickfix.c
@@ -4537,7 +4537,7 @@
     int		len;
     buf_T	*errbuf;
 
-    // If the 'quickfixtextfunc' function returned an non-empty custom string
+    // If the 'quickfixtextfunc' function returned a non-empty custom string
     // for this entry, then use it.
     if (qftf_str != NULL && *qftf_str != NUL)
 	vim_strncpy(IObuff, qftf_str, IOSIZE - 1);
diff --git a/src/regexp_nfa.c b/src/regexp_nfa.c
index 4d7d553..0a07edb 100644
--- a/src/regexp_nfa.c
+++ b/src/regexp_nfa.c
@@ -2334,7 +2334,7 @@
 	    // will emit NFA_STAR.
 	    // Bail out if we can use the other engine, but only, when the
 	    // pattern does not need the NFA engine like (e.g. [[:upper:]]\{2,\}
-	    // does not work with with characters > 8 bit with the BT engine)
+	    // does not work with characters > 8 bit with the BT engine)
 	    if ((nfa_re_flags & RE_AUTO)
 				   && (maxval > 500 || maxval > minval + 200)
 				   && (maxval != MAX_LIMIT && minval < 200)
@@ -4972,7 +4972,7 @@
 
     // First add the state(s) at the end, so that we know how many there are.
     // Pass the listidx as offset (avoids adding another argument to
-    // addstate().
+    // addstate()).
     r = addstate(l, state, subs, pim, -listidx - ADDSTATE_HERE_OFFSET);
     if (r == NULL)
 	return NULL;
diff --git a/src/screen.c b/src/screen.c
index 695318b..320811b 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -614,9 +614,9 @@
 	    }
 	    // When writing a single-width character over a double-width
 	    // character and at the end of the redrawn text, need to clear out
-	    // the right halve of the old character.
-	    // Also required when writing the right halve of a double-width
-	    // char over the left halve of an existing one.
+	    // the right half of the old character.
+	    // Also required when writing the right half of a double-width
+	    // char over the left half of an existing one.
 	    if (has_mbyte && col + char_cells == endcol
 		    && ((char_cells == 1
 			    && (*mb_off2cells)(off_to, max_off_to) > 1)
@@ -1524,8 +1524,8 @@
 	return;
     off = LineOffset[row] + col;
 
-    // When drawing over the right halve of a double-wide char clear out the
-    // left halve.  Only needed in a terminal.
+    // When drawing over the right half of a double-wide char clear out the
+    // left half.  Only needed in a terminal.
     if (has_mbyte && col > 0 && col < screen_Columns
 #ifdef FEAT_GUI
 	    && !gui.in_use
@@ -1653,9 +1653,9 @@
 #endif
 	    // When at the end of the text and overwriting a two-cell
 	    // character with a one-cell character, need to clear the next
-	    // cell.  Also when overwriting the left halve of a two-cell char
-	    // with the right halve of a two-cell char.  Do this only once
-	    // (mb_off2cells() may return 2 on the right halve).
+	    // cell.  Also when overwriting the left half of a two-cell char
+	    // with the right half of a two-cell char.  Do this only once
+	    // (mb_off2cells() may return 2 on the right half).
 	    if (clear_next_cell)
 		clear_next_cell = FALSE;
 	    else if (has_mbyte
@@ -2376,9 +2376,9 @@
 #endif
 	   )
 	{
-	    // When drawing over the right halve of a double-wide char clear
-	    // out the left halve.  When drawing over the left halve of a
-	    // double wide-char clear out the right halve.  Only needed in a
+	    // When drawing over the right half of a double-wide char clear
+	    // out the left half.  When drawing over the left half of a
+	    // double wide-char clear out the right half.  Only needed in a
 	    // terminal.
 	    if (start_col > 0 && mb_fix_col(start_col, row) != start_col)
 		screen_puts_len((char_u *)" ", 1, row, start_col - 1, 0);
diff --git a/src/scriptfile.c b/src/scriptfile.c
index 129d4d6..9c8f1ef 100644
--- a/src/scriptfile.c
+++ b/src/scriptfile.c
@@ -1307,7 +1307,7 @@
 
     current_sctx.sc_lnum = 0;
 
-    // Check if this script was sourced before to finds its SID.
+    // Check if this script was sourced before to find its SID.
     // Always use a new sequence number.
     current_sctx.sc_seq = ++last_current_SID_seq;
     if (sid > 0)
diff --git a/src/spell.c b/src/spell.c
index 9b2d3e8..857a793 100644
--- a/src/spell.c
+++ b/src/spell.c
@@ -1501,7 +1501,7 @@
 
 /*
  * For spell checking: concatenate the start of the following line "line" into
- * "buf", blanking-out special characters.  Copy less then "maxlen" bytes.
+ * "buf", blanking-out special characters.  Copy less than "maxlen" bytes.
  * Keep the blanks at the start of the next line, this is used in win_line()
  * to skip those bytes if the word was OK.
  */
@@ -3260,7 +3260,7 @@
 	    for (; (s = smp[n].sm_lead)[0] == c; ++n)
 	    {
 		// Quickly skip entries that don't match the word.  Most
-		// entries are less then three chars, optimize for that.
+		// entries are less than three chars, optimize for that.
 		k = smp[n].sm_leadlen;
 		if (k > 1)
 		{
@@ -3551,7 +3551,7 @@
 							 && ws[0] != NUL; ++n)
 	    {
 		// Quickly skip entries that don't match the word.  Most
-		// entries are less then three chars, optimize for that.
+		// entries are less than three chars, optimize for that.
 		if (c != ws[0])
 		    continue;
 		k = smp[n].sm_leadlen;
@@ -4033,7 +4033,7 @@
 			arridx[depth] = idxs[n];
 			curi[depth] = 1;
 
-			// Check if this characters matches with the pattern.
+			// Check if this character matches with the pattern.
 			// If not skip the whole tree below it.
 			// Always ignore case here, dump_word() will check
 			// proper case later.  This isn't exactly right when
diff --git a/src/spellfile.c b/src/spellfile.c
index d85432c..14ea7ab 100644
--- a/src/spellfile.c
+++ b/src/spellfile.c
@@ -4920,7 +4920,7 @@
     //
     // The table with character flags and the table for case folding.
     // This makes sure the same characters are recognized as word characters
-    // when generating an when using a spell file.
+    // when generating and when using a spell file.
     // Skip this for ASCII, the table may conflict with the one used for
     // 'encoding'.
     // Also skip this for an .add.spl file, the main spell file must contain
@@ -5720,7 +5720,7 @@
 	    ++wordnr;
 
 	    // Remove extra NUL entries, we no longer need them. We don't
-	    // bother freeing the nodes, the won't be reused anyway.
+	    // bother freeing the nodes, they won't be reused anyway.
 	    while (p->wn_sibling != NULL && p->wn_sibling->wn_byte == NUL)
 		p->wn_sibling = p->wn_sibling->wn_sibling;
 
diff --git a/src/spellsuggest.c b/src/spellsuggest.c
index 255f94d..f21d55f 100644
--- a/src/spellsuggest.c
+++ b/src/spellsuggest.c
@@ -112,7 +112,7 @@
 #define SCORE_THRES3	100	// word count threshold for COMMON3
 
 // When trying changed soundfold words it becomes slow when trying more than
-// two changes.  With less then two changes it's slightly faster but we miss a
+// two changes.  With less than two changes it's slightly faster but we miss a
 // few good suggestions.  In rare cases we need to try three of four changes.
 #define SCORE_SFMAX1	200	// maximum score for first try
 #define SCORE_SFMAX2	300	// maximum score for second try
diff --git a/src/strings.c b/src/strings.c
index 3dd6856..52cf121 100644
--- a/src/strings.c
+++ b/src/strings.c
@@ -171,7 +171,7 @@
     // itself must be escaped to get a literal '\'.
     fish_like = fish_like_shell();
 
-    // PowerShell uses it's own version for quoting single quotes
+    // PowerShell uses its own version for quoting single quotes
     shname = gettail(p_sh);
     powershell = strstr((char *)shname, "pwsh") != NULL;
 # ifdef MSWIN
diff --git a/src/term.c b/src/term.c
index e97ec2c..4757d85 100644
--- a/src/term.c
+++ b/src/term.c
@@ -4460,7 +4460,7 @@
 #endif
 #if defined(CHECK_DOUBLE_CLICK) || defined(PROTO)
 /*
- * Checking for double clicks ourselves.
+ * Checking for double-clicks ourselves.
  * "orig_topline" is used to avoid detecting a double-click when the window
  * contents scrolled (e.g., when 'scrolloff' is non-zero).
  */
diff --git a/src/terminal.c b/src/terminal.c
index 8f80f9f..a88e4bc 100644
--- a/src/terminal.c
+++ b/src/terminal.c
@@ -1591,7 +1591,7 @@
     {
 	job_T *job = term->tl_job;
 
-	// Careful: Checking the job status may invoked callbacks, which close
+	// Careful: Checking the job status may invoke callbacks, which close
 	// the buffer and terminate "term".  However, "job" will not be freed
 	// yet.
 	if (check_job_status)
diff --git a/src/testdir/test_debugger.vim b/src/testdir/test_debugger.vim
index 6f01917..e305033 100644
--- a/src/testdir/test_debugger.vim
+++ b/src/testdir/test_debugger.vim
@@ -948,7 +948,7 @@
 
   call RunDbgCmd(buf, 'step', ['line 1: SourceAnotherFile()'])
   call RunDbgCmd(buf, 'step', ['line 1: source Xtest2.vim'])
-  " Repeated line, because we fist are in the compiled function before the
+  " Repeated line, because we first are in the compiled function before the
   " EXEC and then in do_cmdline() before the :source command.
   call RunDbgCmd(buf, 'step', ['line 1: source Xtest2.vim'])
   call RunDbgCmd(buf, 'step', ['line 1: vim9script'])
diff --git a/src/testdir/test_source.vim b/src/testdir/test_source.vim
index 559208a..8f8e963 100644
--- a/src/testdir/test_source.vim
+++ b/src/testdir/test_source.vim
@@ -69,7 +69,7 @@
   call delete('Xfile.vim')
 endfunc
 
-" Test for expanding <sfile> in a autocmd and for <slnum> and <sflnum>
+" Test for expanding <sfile> in an autocmd and for <slnum> and <sflnum>
 func Test_source_autocmd_sfile()
   let code =<< trim [CODE]
     let g:SfileName = ''
diff --git a/src/textformat.c b/src/textformat.c
index 58ba0ab..920db40 100644
--- a/src/textformat.c
+++ b/src/textformat.c
@@ -527,7 +527,7 @@
     // If first leader has 'f' flag, the lines can be joined only if the
     // second line does not have a leader.
     // If first leader has 'e' flag, the lines can never be joined.
-    // If fist leader has 's' flag, the lines can only be joined if there is
+    // If first leader has 's' flag, the lines can only be joined if there is
     // some text after it and the second line has the 'm' flag.
     if (leader1_flags != NULL)
     {
diff --git a/src/userfunc.c b/src/userfunc.c
index 8f66291..e1028e7 100644
--- a/src/userfunc.c
+++ b/src/userfunc.c
@@ -1035,7 +1035,7 @@
 
 	if (heredoc_concat_len > 0)
 	{
-	    // For a :def function "python << EOF" concatenats all the lines,
+	    // For a :def function "python << EOF" concatenates all the lines,
 	    // to be used for the instruction later.
 	    ga_concat(&heredoc_ga, theline);
 	    ga_concat(&heredoc_ga, (char_u *)"\n");
diff --git a/src/version.c b/src/version.c
index 658d9be..7dd9b49 100644
--- a/src/version.c
+++ b/src/version.c
@@ -750,6 +750,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3914,
+/**/
     3913,
 /**/
     3912,
diff --git a/src/vim.h b/src/vim.h
index 6427380..55bb7cd 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -1012,7 +1012,7 @@
 #define DOBUF_UNLOAD	2	// unload specified buffer(s)
 #define DOBUF_DEL	3	// delete specified buffer(s) from buflist
 #define DOBUF_WIPE	4	// delete specified buffer(s) really
-#define DOBUF_WIPE_REUSE 5	// like DOBUF_WIPE an keep number for reuse
+#define DOBUF_WIPE_REUSE 5	// like DOBUF_WIPE and keep number for reuse
 
 // Values for start argument for do_buffer()
 #define DOBUF_CURRENT	0	// "count" buffer from current buffer
diff --git a/src/vim9.h b/src/vim9.h
index a79ffb5..d2c23be 100644
--- a/src/vim9.h
+++ b/src/vim9.h
@@ -703,7 +703,7 @@
 
     garray_T	ctx_locals;	    // currently visible local variables
 
-    int		ctx_has_closure;    // set to one if a closures was created in
+    int		ctx_has_closure;    // set to one if a closure was created in
 				    // the function
 
     garray_T	ctx_imports;	    // imported items
diff --git a/src/vim9cmds.c b/src/vim9cmds.c
index 4e5336c..d341154 100644
--- a/src/vim9cmds.c
+++ b/src/vim9cmds.c
@@ -840,7 +840,7 @@
 
     if (cctx->ctx_skip != SKIP_YES)
     {
-	// If we know the type of "var" and it is a not a supported type we can
+	// If we know the type of "var" and it is not a supported type we can
 	// give an error now.
 	vartype = ((type_T **)stack->ga_data)[stack->ga_len - 1];
 	if (vartype->tt_type != VAR_LIST
diff --git a/src/vim9execute.c b/src/vim9execute.c
index 9814f25..fd53630 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -544,7 +544,7 @@
 	    int refcount = pt->pt_refcount;
 	    int i;
 
-	    // A Reference in a local variables doesn't count, it gets
+	    // A Reference in a local variable doesn't count, it gets
 	    // unreferenced on return.
 	    for (i = 0; i < dfunc->df_varcount; ++i)
 	    {
diff --git a/src/winclip.c b/src/winclip.c
index db88e67..560759e 100644
--- a/src/winclip.c
+++ b/src/winclip.c
@@ -147,7 +147,7 @@
 	LPWSTR *out, int *outlen)
 {
     *outlen = MultiByteToWideChar(cp, flags, in, inlen, 0, 0);
-    // Add one one word to avoid a zero-length alloc().
+    // Add one word to avoid a zero-length alloc().
     *out = ALLOC_MULT(WCHAR, *outlen + 1);
     if (*out != NULL)
     {
@@ -167,7 +167,7 @@
 	LPCSTR def, LPBOOL useddef)
 {
     *outlen = WideCharToMultiByte(cp, flags, in, inlen, NULL, 0, def, useddef);
-    // Add one one byte to avoid a zero-length alloc().
+    // Add one byte to avoid a zero-length alloc().
     *out = alloc(*outlen + 1);
     if (*out != NULL)
     {
diff --git a/src/window.c b/src/window.c
index 4ee75c1..ca35e5b 100644
--- a/src/window.c
+++ b/src/window.c
@@ -1555,7 +1555,7 @@
 
     if (vertical)
     {
-	// Each windows needs at least 'winminwidth' lines and a separator
+	// Each window needs at least 'winminwidth' lines and a separator
 	// column.
 	maxcount = (curwin->w_width + curwin->w_vsep_width
 					     - (p_wiw - p_wmw)) / (p_wmw + 1);
@@ -2109,7 +2109,7 @@
 	    room = height - m;
 	    if (room < 0)
 	    {
-		// The room is less then 'winheight', use all space for the
+		// The room is less than 'winheight', use all space for the
 		// current window.
 		next_curwin_size = p_wh + room;
 		room = 0;