가 많아

there are a lot of

→ 가
phrase Common #2,167
there are a lot of 가 marks the subject, and 많아 is the casual form of 많다, meaning “to be many” or “to be a lot.”
KO: 필요한 소리가 많아.
EN: There are a lot of sounds needed.

가끔 그 앨 보면 진짜 내 아들이 맞나 싶을 때가 많아

Sometimes I look at him and wonder if he's really my son.

— 음식남녀 (1994)