diff --git a/addon/edit/matchbrackets.js b/addon/edit/matchbrackets.js
index c342910ed5..0d1bcb662e 100644
--- a/addon/edit/matchbrackets.js
+++ b/addon/edit/matchbrackets.js
@@ -27,7 +27,7 @@
       afterCursor = /(^| )cm-fat-cursor($| )/.test(cm.getWrapperElement().className)
     var re = bracketRegex(config)
 
-    // A cursor is defined as between two characters, but in in vim command mode
+    // A cursor is defined as between two characters, but in vim command mode
     // (i.e. not insert mode), the cursor is visually represented as a
     // highlighted box on top of the 2nd character. Otherwise, we allow matches
     // from before or after the cursor.
diff --git a/doc/manual.html b/doc/manual.html
index 9951e08cca..553ac6c731 100644
--- a/doc/manual.html
+++ b/doc/manual.html
@@ -3733,7 +3733,7 @@ <h3 id="vimapi_extending">Extending VIM</h3>
       been mapped to their Vim equivalents. Finds a command based on the key
       (and cached keys if there is a multi-key sequence). Returns <code>undefined</code>
       if no key is matched, a noop function if a partial match is found (multi-key),
-      and a function to execute the bound command if a a key is matched. The
+      and a function to execute the bound command if a key is matched. The
       function always returns true.
       </dd>
 
diff --git a/src/display/update_lines.js b/src/display/update_lines.js
index f09524b605..efb68f4479 100644
--- a/src/display/update_lines.js
+++ b/src/display/update_lines.js
@@ -58,7 +58,7 @@ function updateWidgetHeight(line) {
 }
 
 // Compute the lines that are visible in a given viewport (defaults
-// the the current scroll position). viewport may contain top,
+// the current scroll position). viewport may contain top,
 // height, and ensure (see op.scrollToPos) properties.
 export function visibleLines(display, doc, viewport) {
   let top = viewport && viewport.top != null ? Math.max(0, viewport.top) : display.scroller.scrollTop