"Close your book!"
It is technically correct, but native speakers will say "bukumu" instead of "buku kamu"
...setujuh 'bukumu' itu lebih biasa, tapi kalau pidato atau tulisan formal, tetapkah memakai 'bukumu' atau 'buku kamu'? terima kasih banyak sebelumnya
@boringtomi ...as far as i remember the particle "-lah" as a suffix for a verb turns the verb into an imperative, so in certain situations it should be correct (but may not be normally used on a daily basis or in common conversations, i'm not quite sure)
suffix "-lah" is indeed normally used on common conversation..
In colloquial conversation, Bahasa Indonesia speakers from Central and east java often replace the suffix "-lah" with the javanese version "o", so in daily conversation in the area where javanese is the native language you will hear more: "Bukao bukumu", "Tutupo bukumu" than "Bukalah bukumu" and "Tutuplah bukumu"...