must与have to的区别 知识梳理与专项练习知识梳理
must与have to在英语中都表示“必须”的意思，但他们之间存在一些基本区别。
1.含义的区别：
must：必须（主观），表示主观上的强烈意愿或命令，强调个人主观的决定或判断。
have to：不得不（客观）表示由于某种外部情况或条件而必须采取行动，强调客观必要性。
2.时态的区别：
must：没有时态变化，只有现在时一种形式 (在宾语从句中可以表示过去)。
例：He said she must go with me. 他说她必须同我一起去。
have to：随时态变化而变化，通过助动词来体现。
例：现在时态下，have to可以表达为“have to do”，而must则为“must do”。
3.肯定句的区别：
must：must do
have to：have/has/had to do, will have to do
4.否定式意义的区别：
must：must的否定形式must not=mustn't，表示“一定不要、不允许、禁止、不准。”逾期不交强烈。在回答 must 的问句时， 肯定形式用 must 来回答 但否定形式用needn't 或don't have
to 来回答。而不用 mustn't来回答。
例：You mustn't tell him about it. 你一定不要告诉他这件事。(这可能是秘密)。
-Must I be home before 8 o'clock ( 8 点之前我必须回家吗 )
-Yes, you must. 是，你必须。
-No, you needn't. /No, you don't have to. 不，你不必。
have to：与否定词not连用，表示“不必”或“不需要”的意思don't/ doesn't /didn't/won't have to do
例：I don't have to go我不必去。
5.表示对过去的推测意义时的区别：
must：直接使用过去时态。
例：They must go他们必须走。
have to：使用过去完成时态。
例：They must have gone他们一定已经走了。
专项练习
一、选择题。
1.-Listen! Is Professor Li giving a speech in class
-No, it _____ be him. He has gone to France.
A. may not B. mustn't C. needn't D. can't
2. -Will you answer the telephone
-Sorry. It _____ be your mother.
A. can; mustn't B. may; won't
C. may; can't D. need; will
3. Four hundred dollars for a pair of shoes, you _____be joking!
A. may B. can C. need D. must
4. I'm sorry. I _____ go now. My father told me on the phone that my mother was ill.
A. can B. may C. have to D. think
5.-May l put my bike here
-No, you _____.You should put it over there.
A. couldn't B. needn't C. mustn't D. won't
6. If you know nothing about the famous program called Where are we going, dad You _____ be living in a box!
A. would B. can C. must D. need
7.-Can you go shopping with us this afternoon
-Sorry, l can't. I _____look after my little sister.
A. can B. may C. have to D. need
8.-May l smoke here
-No, you _____. This is a no-smoking room.
A. needn't B. mustn't C. need D. wouldn't
9. Someone is knocking at the door. It _____be my mother.
It's time for her to be back.
A. can B. may not C. must D. mustn't
10. You _____take me to the station. My brother's taking me
A. can't B. mustn't
C. shouldn't D. don't have to
11. -Sorry, Miss Liu. I left my workbook at home. Must l hand it in(上交它) today
-No, you _____. You _____bring it here tomorrow
A. mustn't; should B. can't; must
C. mustn't; may D. needn't; can
12. The children _____ play basketball on the road.
A. can't B. can C. mustn't D. must
13. You _____ go and see a doctor at once because you got a fever(发烧).
A. can B. must C. dare D. would
14. -Mum, must l finish the homework now
-No, you _____.You can do it after supper.
A. needn't B. mustn't C. can't D. may not
15. Sorry! I can't follow you. I _____finish my homework first.
A. can B. may C. must D. could
答案
一、DCDCC CCBCD DCBAC
