This pattern is used to indicate the speaker’s presumption or conjecture.
– used with any verb usually with the subject in the third person.
– these pattern is used when you don’t have direct evidence of the conjecture you are talking about.
● 땀을 흘리는 걸 보니 매운가 봐.
● 냄새가 나네. 윗집에서 삼겹살을 먹나 봐.
● 이게 요즘 잘 팔리는 책인가 봐.