To be obliged or required by morality, law, or custom.
예문
1. I must be going now. (이제 가야겠습니다) 2. I must say, you look very handsome today. (너 오늘 정말 멋지게 보인다) 3. You must know this! -> Must I? (당신은 이것을 틀림없이 알고 있을 테지 -> 제가요) 4. I told him that I must go. (나는 그에게 내가 가야 한다고 말했다) 5. You must have caught the train if you had hurried. (서둘렀더라면 틀림없이 기차 시간에 댔을 터인데)
