1
must + [verb] (necessity)
must表示主观义务或必要性，否定形式用mustn't表示禁止。
You must finish your homework before watching TV.
你必须先完成作业才能看电视。
必须；一定
先理解核心含义，再看它在真实句子里的用法。
必须；一定
used for strong necessity or a conclusion believed to be certain
You must finish your homework before watching TV.
你必须先完成作业才能看电视。
可表示强烈的必要性，也可表示有充分依据的肯定推断。
must
Base
原形
must
3rd person
第三人称单数
must
Past
过去式
情态动词 must 没有 -ing 形式或过去分词，也不使用普通的第三人称单数 -s 变化。
You must wear a seat belt in the car.
你在车里必须系安全带。
She must be tired after such a long day.
忙了这么长一天，她一定累了。
Visitors must not enter this room.
访客禁止进入这个房间。
must表示主观义务或必要性，否定形式用mustn't表示禁止。
You must finish your homework before watching TV.
你必须先完成作业才能看电视。
mustn't是must的否定形式，强调禁止。表示‘不必’时用don't have to。
You mustn't park here; it's a fire lane.
你不能在这里停车，这是消防通道。
must表示对现在的肯定推测，语气较强。
He's been working all day; he must be tired.
他工作了一整天，肯定累了。
Not this
I must go to the store yesterday.
Use this
I had to go to the store yesterday.
must 没有过去时形式，需要用 had to 表示过去的必要性。
Not this
You mustn't finish your homework; it's not required.
Use this
You don't have to finish your homework; it's not required.
mustn't 表示禁止，而‘不必’应该用 don't have to 或 needn't。
Focus on the distinctions below. Other candidates are kept compact until a reliable usage note is available.
必须有；一定有的
A passport is a must-have for international travel.
护照是国际旅行的必备品。
一定是；肯定是
You must be tired after such a long journey.
这么长的旅途之后你一定很累。
必须做
This is a must-do task before the deadline.
这是在截止日期前必须完成的任务。
必看
That new movie is a must-see for all film lovers.
那部新电影是所有电影爱好者的必看之作。
必读
This book is a must-read for anyone interested in history.
这本书是对历史感兴趣的读者的必读之作。
必须赢；必胜
The team considers this match a must-win situation.
该队认为这场比赛是必胜的局面。
如果你非得这样
You can go, if you must, but be careful.
如果你非得去就去吧，但要小心。
非得，偏要
He must needs go against the rules.
他偏要违反规则。
那一定是爱
The song 'It Must Have Been Love' by Roxette contains the line 'It must have been love, but it's over now'.
罗克塞特乐队的歌曲《那一定是爱》中有句歌词是'那一定是爱，但现在结束了'。
我决不能恐惧
In the movie Dune, Paul Atreides recites the litany 'I must not fear' to master his fear.
在电影《沙丘》中，保罗·厄崔迪背诵'我决不能恐惧'的咒语来控制恐惧。
Use must naturally, then get feedback on meaning, tone, grammar, and phrasing.
Revisit a common error or keep this word in your review list.
must发音似'骂死他'，用来强调必须做的要求。
语域：neutral 常见场景：日常交流、书面规则、逻辑推理 must 是英语中最基本的情态动词之一，表达必要性或强推测，A1 级别学习者即可使用。它既适用于口语对话，也常见于正式书面语，因此语域归为中性。
must 后接不带 to 的动词原形。mustn't 表示“禁止”，而“不必”通常用 don't have to 或 needn't。
Dictionary facts from BRIDGEDICT_CURATED_MODAL, CEFR_J, DICTIONARY_API_DEV.