무슨 생각을 하는지

what someone is thinking

→ 무슨
phrase Common #5,999
what someone is thinking The person doing the thinking is usually understood from context. Often used as part of a larger sentence or question.
KO: 그 사람이 무슨 생각을 하는지 모르겠어요.
EN: I don’t know what that person is thinking.

데이비드는 내가 무슨 생각을 하는지 알아차리지 못했던 것 이다.

David hadn't realized what I was thinking.

그런데 요즘은 도통 무슨 생각을 하는지…

But these days, I really can't tell what you're thinking...

— 추억의 마니 (2014)

무슨 생각을 하는지 몰라도 지금 실수하는 거 라고요 그렇게 보지 말아요

I don't know what you're thinking, but you're making a mistake right now. Don't look at it that way.

— 특별한 날 (1977)

얘가 무슨 생각을 하는지 누가 알 수 있을까요?

Who knows what he's thinking?

— 400번의 구타 (1959)