Press the on your controller and select Manage Game Content . Scroll to Language Data . Locate the English pack and select the Download icon .
Open your and right-click on Call of Duty: Modern Warfare III (or the 2011 version). Select Properties > Language . Select English from the dropdown menu. Download Modern Warfare 3 English Language Pack
If you are playing the older version of MW3 and the platform options aren't working, you may need to manually swap files. Press the on your controller and select Manage Game Content
Steam is the most common platform for MW3. You do not usually need to download an external "pack"; Steam handles it automatically. Close the game. Download Modern Warfare 3 English Language Pack