Yap.Town

있다는 건

that ... exists; that ... is there

→ 있다
phrase Uncommon #15,303
that ... exists; that ... is there 건 is a shortened form of 것은, marking the fact that something exists or is present.
KO: 네가 여기 있다는 건 알고 있었어.
EN: I knew you were here.

그런 사람이 있다는 건 뻔히 알 수 있었지만.

It was obvious that someone like that existed, though.

세이타, 다들 할 일이 있다는 건 너도 알 나이가 됐잖아

Seita, you're old enough to know that everyone has things they need to do.

— 반딧불의 묘 (1988)

내가 있다는 건 아셔?

Do you know I exist?

— 어바웃 타임 (2013)