How do I change language in Outlook?
Open Outlook (1).
Click on File (2).
Select Settings at the menu to the left (3).
Select Language at the menu to the left (4). If you want to change spelling, grammar, etc. choose a language under Choose editing languages (5). Click Set as default (6).
If you want to change the language of tabs, buttons, and other controls, select the language under Choose Display Language > Display language (7). Select Set as default (8).
Press OK (9) to save changes.