Close your books = not accepted.
I think it should be accepted as well.
Especially since "kalian" (plural you) is being used in the sentence.
It's reasonable to assume that we're talking about more than one book.
I agree, unless somehow a group of people are sharing a book but that seems unlikely
It's accepted now.
I was thinking exactly the same.
Shut your books should also be accepted
Says sering perlu ini di kelas
Why is it nit necessary to use the men- prefix as "menutup" to make it a verb?
When a verb is used in an imperative sentence, the 'me-' prefix is dropped.
buku kalian = yʻallʻs books
Buku kalian is plural. Book changes to books but "y'all's" does not exist except in US southern slang. Perhaps you were having a joke.