Office uses the default input language in the Windows operating system to determine the default language for Office programs. For example, if the default input language for the Windows operating system is Japanese, the default language for all Office programs is also Japanese.
Important
It is NOT usually necessary to change the Windows input language to work with multiple languages in Office. Most language needs can be met by doing one of the following:
Add a language to Office or change the display, Help, and ScreenTip language
If you're having trouble with languages and you're not sure if you want to change the language in Windows, read Troubleshoot checking spelling and grammar in multiple languages first.
If you have a Microsoft 365 Family or Personal subscription, or a one-time purchase of Office, and you want to permanently change the language of your Office installation, see Choose or change the language of your Office installation for another option.
Change the default input language for Windows
From the Start menu, search for Control Panel, and open Control Panel.
Under Clock, Language, and Region, click Change input methods.
Note
If you don't see Clock, Language, and Region, click Category in the View by menu at the top of the page.
Optional: Click Add a language to add a new language. Select the language you want to add and click Add.
Select your language, click Options, and then click Add an input method to add the input language you want. The default input language will be the first language in your language list.
See Also
Add a language or set language preferences in Office
Check spelling and grammar in a different language in Office
Enable or change the keyboard layout language