넌 누군데

who are you?

→ 너+는
phrase Rare #29,140
who are you? Informal and often confrontational; depending on context, it can mean “who do you think you are?”
KO: 넌 누군데 내 이름을 알아?
EN: Who are you, and how do you know my name?

넌 누군데 도망치는 거 지?

Who are you to be running away?

— 얼지마, 죽지마, 부활할거야 (1990)

넌 누군데?

Who are you?

— 세 얼간이 (2009)

몰라, 넌 누군데?

I don't know, who are you?

— 로우 (2017)

잘됐네, 넌 누군데?

That works out well—who are you?

— 걸리 보이 (2019)