How do you use "must" in a sentence?

You must wear a seatbelt in the car. She must be at least forty years old. This film is a must-see.

must

Vocabulary Word BritishAmerican ★★★★★ Very Common Neutral

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Meaning: Used to express obligation, necessity, or logical conclusion

必须；一定

deber, tener que; seguramente

〜しなければならない；〜に違いない

~해야 한다; ~임에 틀림없다

'Must' is a modal verb expressing strong obligation ('you must attend'), logical deduction ('she must be tired'), or strong recommendation ('you must try this restaurant'). Unlike 'have to', 'must' implies the speaker's personal insistence. 'Must not' expresses prohibition, while 'don't have to' means no obligation.

「must」是一个情态动词，表示强烈的义务（「you must attend」）、逻辑推断（「she must be tired」）或强烈推荐（「you must try this restaurant」）。与「have to」不同，「must」暗示说话者个人的坚持。「must not」表示禁止，而「don't have to」表示没有义务。

«Must» es un verbo modal que expresa obligación fuerte («you must attend»), deducción lógica («she must be tired») o recomendación fuerte («you must try this restaurant»). A diferencia de «have to», «must» implica la insistencia personal del hablante. «Must not» expresa prohibición, mientras que «don't have to» significa sin obligación.

「must」は強い義務（「you must attend」）、論理的な推論（「she must be tired」）、または強い推奨（「you must try this restaurant」）を表す助動詞です。「have to」とは異なり、「must」は話者の個人的な主張を暗示します。「must not」は禁止を表し、「don't have to」は義務がないことを意味します。

'Must'는 강한 의무('you must attend'), 논리적 추론('she must be tired'), 또는 강한 추천('you must try this restaurant')을 나타내는 조동사입니다. 'have to'와 달리 'must'는 화자의 개인적 주장을 내포합니다. 'Must not'은 금지를 나타내고, 'don't have to'는 의무가 없음을 의미합니다.

Examples

You must wear a seatbelt in the car.
在车里你必须系安全带。
Debes llevar el cinturón de seguridad en el coche.
車ではシートベルトを着用しなければなりません。
차 안에서는 반드시 안전벨트를 착용해야 합니다.
She must be at least forty years old.
她至少得有四十岁了。
Ella debe tener al menos cuarenta años.
彼女は少なくとも40歳に違いありません。
그녀는 적어도 마흔 살은 됐을 것입니다.
This film is a must-see.
这部电影是必看之作。
Esta película es imprescindible.
この映画は必見です。
이 영화는 꼭 봐야 합니다.

Pronunciation

Usage Guide

Context: general

Tone: neutral

Origin & History

From Old English 'mōste', past tense of 'mōtan' (to be allowed). Uniquely, the original meaning was 'permission' — the same as 'may'. Over time, it shifted to express obligation and necessity, essentially reversing from 'allowed to' to 'required to'.

Cultural Context

Era: Modern

Generation: All ages

Social background: Universal