Can you just say "bạn ở ngoài không? "
Yeah you can. Well, for everyday speech you can. I don't think it's formal or "proper" though.
A text message!
I thought it's "being outside" because of the "đang"
Well it means "to currently be" and the question form already has "are". The English question implies that it's in the present.
I got "are you currently outside?" wrong, which I think should also be considered correct
what about 'bạn có ra ngoài không? '
that means "are you going outside? "