how to you ask korean boys " Have you had to serve your duty in the korean military yet? in Korean

Question

Answer

if the boy is in the military, then "너 아직 군대에 있어야 돼?/너 아직 군대 안 마쳤어?"
if he is not in the military still without serving his duty, then "너 군대 가야돼?/너 아직 군대 안 마쳤어?"
너 아직 군대에 있어야 돼? = do you have to be in the military yet?
너 아직 군대 안 마쳤어? = haven't you finished serving the military?
너 군대 가야돼? = do you have to go to the military?(in literal meaning in korean)/do you have to join the military?

Answer

군대 갔다 오셨어요?
군대 갔다 왔어요?