Where does the language come from in Book Details?

Hi everyone,

I noticed that most of my book in foreign language are considered "ENGLISH" when I check them up in the Details area of my Kobo.

It is not the case for Italian, or German books. Is the list of languages limited iin the details section, or are the books in "Sanskrit" "chinese", "arabic" also labeled english on your Kobos?

Thank you for your comparison effort.
(Kobo aura HD 3.8)

François