Hi

Are you able to provide some some of the text so we can identify the language?

This will help me to walk you through the menu options to change the language back.

I need to change my language on Firefox back to English. How can I change my settings when I don't understand the language it is written in?

Click on thee three dots in upper right corner. From the drop down menu select the last option which is of setting. Now under the second category (which is of general, just below the account category which one might not be able to recognise because of changed language) select the second last subcategory and click on the first option. This would force the firefox back into your device language. I hope this should help switching you back to the desired language.

Your the bestest