있어서 그래

that's because there is/are

→ 있다
phrase Uncommon #11,189
that's because there is/are The reason or thing that exists is usually clear from context.
KO: 집에 손님이 있어서 그래.
EN: That's because I have guests at home.

문 열어, 볼 일이 있어서 그래

Open the door. I need to talk to you about something.

— 아마코드 (1973)

어디 갈 데가 있어서 그래

I have somewhere I need to go.

— Tune in for Love (2019)

누나는 멀리 있어서 그래

It's because my older sister is far away.

— 특별한 날 (1977)