If you need to update the entire game to a different language, you generally cannot do this inside the game menu. You must use your game launcher:

This guide covers everything from basic language switching to advanced mod translation updates. 1. How to Update Your Game Language

: Open the app, go to Settings > Application > Language . Note that changing the app language may not automatically change the game; you might need to right-click the game in your library, select Properties , and look for Advanced Launch Options to set the Game Language .

: Right-click The Sims 4 in your Library, select Properties > General , and choose your language from the dropdown.