must、haveto区别及专项重点学习的练习

must与have to的差别
神态动词must 和 have to都有“一定”的含义，它们的用法以下：
（一）、must “一定”、“应当”的用法:表示“一定”、“应当”。

比如：
① We must protect our environment.(我们一定保护环境。

）
② Everyone must obey the rule.（人人一定恪守制度。

）
2. must的否认形式must not表示“不该当”、“严禁”、“严禁”。

语气比较激烈。

例如：
① You mustn’t speak like that.(你不该当像那样发言。

）
②You mustn’t be late for school.（你不该当上学迟到。

）
3. 在回答 must 的问句时，一定形式用must 往返答，但否认形式用needn’t或don’t have to 往返答。

而不用mustn’t往返答。

比如：
①—— Must I be home before 8 o’clock(8点以前我一定回家吗)
—— Yes, you must.No, you n eedn’t./No, you don’t have to.
（是，你一定。

）（不，你不用。

）
（二）、 have to表示“一定”、“不得不”，比如：
① He has to stay in bed for 3 or 4 days.(他一定卧床歇息三四天。

）
② We will have to get up early tomorrow.（明日我们一定早起。

）
增补： have got to是have to的口语形式。

比如：
①I ’ve got t o leave for Nanjing.(我不得不去南京。

)
* Must 与 have to的差别：
must 表示的是说话人的主观见解，而have to则表示的是客观需要。

Must 一般只有此刻时，而 have to有更多的形式。

① I must go now.(主观见解)
② My mother is ill, so I have to go now.(客观需要)
* Have to与have got to的差别：
have got to固然是have to的口语形式，但两者在用法上有严格的差别：have to的前方还能够用神态动词或助动词，而have got to却不能够；have to的否认形式为don’t/doesn ’t /didn’t +have to,疑问式为Do/Does/Did +主语+ have to⋯而have got to的否认形式是在have 后加 not,疑问式把have 提早。

比如：
①We don’t have to go home.①Do you have to go home
②We haven’t got to go home. ②Have you got to go home
专项练习 1
I do it now
-----No, you _______.
A. needn’ t
B. don’t have to
C. mustn’ t
D. A or B
’s nearly seven o’ clock. Jack ______be here at any time.
A. must
B. need C should D can.
can I come for these photos I need them tomorrow afternoon.
-------They ____be ready by 12:00. A. can B. should C. might D. need
___ do well in the exam.
A. can be able to
B. be able to
C. can able to
D. are able to
5, -Could I take this book out
-No, you___.
A. can't
B. couldn’t
C. needn't
D. aren't
6.You___ go and see a doctor at once because you're got a fever.
A. can
B. must
C. dare
D. would
you speak Japanese
-No, I____.
A. mustn't
B. can't
C. needn't
D. may not
8. Even the top students in our class can't work out this problem, so it___ be very difficult.
A. may
B. must
C. can
D. need
9.He isn't at school. I think he ___ be ill.
A.can
B. shall
C. must
D. has to
10.The children___ play football on the road.
A.can't
B. can
C. mustn't
D. must
arm is all right. He___ go and see the doctor.
A. has not to
B. don't have to
C. haven't to
D. doesn't have to
12.Excuse me. ___ you please pass me that
cup A. Do B. Should C. Would D. Must
13.-Would you like to go boating with us
-Yes, ___.
A. I'd like
B. I want
C. I'd like to
D. I do。