Kik vannak hátul ? = Who ARE in the back ?
No, English uses the singular for a question like this. "Who is in the back?" is correct even if you are expecting that the answer will be multiple people.
Thanks. It is not the first time I see a question like that, so probably I was wrong until now.
Is 'Ki van hátul?' all right, too?
Why is it not correct to say kik hátul vannak?
I keep forgetting this myself: The Verb always goes After the Question Word. I'm certain there are exceptions, but this is repeatedly shown throughout duolingo. Question, Verb, rest of sentence.
Both good: "Kik vannak hátul?" "Hátul kik vannak?"