Terjemahan:He reserves a room.
Apa beda "orders" dan "reserves"
"Order" is for goods or things like the ones you find in a store.
A room can be reserved or booked.
Why i can't use "he books"
"Books" is accepted. He books a room = ok.
how about order?
Order is only for things that you can pre-buy in a shop.
You can order a book if the seller doesn't have it in his shop for instance.