refers to a person or thing not close to the speaker
I want the book that is on the top shelf.
최상단 선반에 있는 그 책을 원합니다.
refers to something already mentioned or known
I don't like that she's always late.
그녀가 항상 늦게 오는 것이 마음에 들지 않습니다.
refers to a type of person or thing
I prefer this over that.
저는 그보다 이쪽을 선호합니다.
used to introduce a clause about the person or thing mentioned
I heard that you won the lottery!
당신이 복권에 당첨되셨다는 걸 들었어요!
used to introduce a clause after verbs, adjectives, and nouns
I believe that she will win.
저는 그녀가 이길 것이라고 믿습니다.
used to express a result
She was so tired that she fell asleep at her desk.
그녀는 너무 피곤해서 책상에서 잠이 들었습니다.
used to express a wish or hope
I wish that I could fly.
날 수 있다면 얼마나 좋을까요.
to such an extent
I am not that interested in the topic.
저는 그 주제에 그렇게 관심이 없습니다.
used to show the size, length, etc. of something
The room is that big.
방은 그렇게 크지 않아요.
not very, not as much as stated
I am not that hungry.
저는 그렇게 배가 고프지 않아요.
used for emphasis
I was that scared I couldn't move.
너무 무서워서 움직이지 못했습니다.