Sending, receiving, and organizing email in Outlook.com
Hi,
If your emails are in English but the Outlook menus, folders, and settings are displayed in another language, please change the Outlook display language:
Settings > General > Language and time > select English > Save.
Then refresh Outlook or sign out and sign back in.
Microsoft guide: https://support.microsoft.com/en-us/outlook/getstarted/manage-language-settings-in-outlook
I hope this helps.