조사할 게

something to investigate

→ 조사하다
phrase Rare #30,527
something to investigate 게 is a shortened form of 것이, meaning “thing” in this construction.
KO: 아직 조사할 게 많아요.
EN: There are still many things to investigate.

조사할 게 있어

I have something to look into.

— 다이 하드 (1988)

질란트 양 조사할 게 있으니 따라오시오

I have something to investigate regarding the Zealand sheep, so follow me.

— 타인의 삶 (2006)

조사할 게 있어서 갔지

I went there because I had something to investigate.

— 아메리칸 갱스터 (2007)