If you have a document that is available in more than one language, you can give the Q&A user the option to change its language.
In Design Q&A mode, there is a special type of question pre-made just for this use case. Click the 
or the 
button and choose the 
option. Like any other question, you can choose the text of the question. It will give the user the option to change the output language of the document.