Click the cogwheel (Settings) icon next to the Play button. Select Game Settings , then use the dropdown to change the Text & Spoken Language to English. The launcher will begin a small update to download the new assets. On Console (PS5, PS4, Xbox)
For the modern version of the game, language packs are managed through the game client or the launcher. english language pack for call of duty modern warfare 2
If the in-game settings don't work, ensure your Console Location and Language are set to English/United States in the system settings, as some Xbox Game Pass versions default to the console's regional language. Click the cogwheel (Settings) icon next to the Play button