are waiting in line, are lined up
ここ何で並んでるんですか？
Why are people lining up here?
皆並んでるんだ
Everyone is lining up.
— 自転車泥棒 (1948)
どうして並んでるの？
Why are you standing in line?
朝からずっと並んでるんだ。
I've been waiting in line since this morning.
ドアの外まで並んでるよ。
The line stretches all the way outside the door.