뭔지 알아요

know what it is

→ 뭐+이+ㄴ지
phrase Rare #21,227
know what it is Often used in questions meaning “Do you know what it is?” The thing being asked about is usually stated or understood from context.
KO: 이 버튼이 뭔지 알아요?
EN: Do you know what this button is?

당신은 뭔지 알아요?

Do you know what?

— 캐치 미 이프 유 캔 (2002)

이게 뭔지 알아요?

Do you know what this is?

— 저수지의 개들 (1992)

이름이 뭔지 알아요?

Do you know what the name is?

— 8과 1/2 (1963)

그게 뭔지 알아요?

Do you know what that is?

— 특별한 날 (1977)