Google Language Lock од Zap

Google can automatically detect your language from cookies, location, and browser settings. This extension lets you lock Google's language settings and optionally override the Accept-Language request header.
In private mode, Google does not have access to the cookies from your normal browsing session, so it may fall back to different language settings. This extension fixes that by adding the hl=xx language parameter to Google searches.
You can also optionally override the Accept-Language request header.

If you have any issue or want to report a bug here is my github

Credits

Icons used in this extension:

Location icon:
https://www.flaticon.com/free-icon/local_3832936

Lock icon:
https://www.flaticon.com/free-icon/padlock_2889676

Icons provided by Flaticon creators.