What about, 'They are not reading Chinese books?'
I don't see why Chinese and Mandarin are not interchangeable in the English translation.
Dialects other than mandarin are still written the same way, just spoken differently. Plus, the provided Chinese doesn't specify that the books are supoosed to be in Mandarin at all.
Isn't 语 supposed to pertain specifically to spoken language, though?
So could “他们不看中文书。“ be used for anything?
Would " They can't read Chinese books" be wrong?
I think that would be 他们不会看汉语书 or 他们不能看汉语书