Dear respected Stephanie Todd,
Good day! Thank you for posting to Microsoft Community. We are happy to help you.
I’m sorry you’re having a problem but based on your description we can work together to resolve it.
For the situation you encountered, we deeply understand the inconvenience caused and apologize for it.
As per your description, firstly may I know are you sign-in Microsoft Form using work/school account or personal account? based on my test the Multilingual option is still available in Microsoft Form, see image below for your reference:
As you mentioned, "I need to translate a questionnaire made in MS Forms" to control the form interface language, you can also add a parameter with a specific language code identifier at the end of the URL. For example add ( &lang=***** ) at the end of your survey link
For your reference; Language settings for Microsoft Forms - Microsoft Support
Please understand that our initial reply may not always immediately resolve the issue. However, with your help and more detailed information, we can work together to find a solution.
I'm sorry and I apologize for that.
Appreciate your patience and understanding and thank you for your time and cooperation.
Sincerely,
Waqas Muhammad