는지 보다

check whether; see what

Going and finding out. Half these lines are 있는지 보다, checking whether something exists, which is exactly what you want at a counter: 지금 남은 좌석이 있는지 볼게요 'let me check whether there are seats left.' With a question word it is 'see what': 어느 날 민지가 점심시간에 뭐 하는지 봤어요, 어떤 메시지들이 들어와 있는지 볼까요? Compare 는지 알다, which is already knowing rather than going to look.