Books in multiple languages

[Elon]

I just added a book with basis in German, about learning Italian ( https://www.goodreads.com/book/show/1... ), and started wondering what language to set it as.

I have found no info in the Librarian guide, but I feel like it makes the most sense to use the language it's aimed at (German in this case), but logically it could also lean heavily on Italian as well. Just for clarity: how do we mark books with multiple languages?

[lethe]

Books in multiple languages should get 'mul' in the language field, and in the description field the actual languages can be noted, f.e. "Text in English and Spanish".

A textbook for learning a language is different, though. As you said, in this case German is the language that should be added.

[Elon]

I had missed the "multiple languages" category, actually. It really makes sense.
Thanks for pointing that out, and for confirming my suspicion on the textbook!