高中英语情态动词讲解和练习.doc

高中英语情态动词讲解和练习
必修3第一单元要学的情态动词有：can/could;may/might;shall/should; will/would;must.注意：情态动词后面接动词原形，通常只有原形和过去式两种形式.(be able to 和 have to除外)
1、can和could (could为can的过去式) 的基本用法
(1)表示能力，如：He can speak English better than you.
(2) 表示“许可”时，can可以和may换用，如：You can (may) go home now.
(3) 在疑问句和否定句中表示“怀疑”、“猜测”或“可能性”，如：Can this green bike be Liu Dong's?
How can it come about ?
(4)如果要表示语气婉转，可用could代替can，这时could不再是can的过去式，如：Could you come again tomorrow?
(5)can和be able to都可表示能力，两者在意思上没有什么区别。但是can只能有现在式和过去式，而be able to则有更多的形式，还表示经过一番努力才“能”做到某事。如：He will be able to do the work better
.
2、may和might (might为may的过去式)的基本用法
(1)表示允许或征询对方许可，有“可以”之意，如：You may use my dictionary.对于一般疑问句的肯定回答一般不用may来回答而用别的词。如：---- May I use this dictionary? ---- Yes, please. 或 ---- Certainly;否定回答用mustn’t，表示禁止“不行，不可以”。如：---- May we swim in this lake? ---- No, you mustn’t. It’s too dangerous.表示请求对方许可时，might比may更委婉些。
(2)may或 might都可以表示可能性，译为“或许”、“可能”，但是might语气更加不肯定，如：They may (might) be in the library now .
（3）may位于句首可以用来表示祝愿。
如：May you succeed！May you have good luck!
3、shall的基本用法
(1)shall用作情态动词时，用于第二、三人称，表示说活人的意愿，可表示“命令”、“警告”、“强制”、“威胁”或“允诺”等意，如：He shall go first, whether he wants to or not.
You shall not leave school.
(2)在疑问句中，shall用于第一、三人称，表示说话人的征询对方意见或请求，如：Shall I open the door?
(3) 在条约，规章，法令等文件中表示义务或规定，用于第三人称。如：According to the law,his wealth shall be given to the city Venice.
4、should的基本用法
(1)should表示“建议”或“劝告”，译为“应该”，应当”，可用于各人称。如：You should learn from each other.
You should keep your promise.
（2）表示推测或可能性，常常是按常规经验来判断，译为“按理说”。
We should have 12 tickets.
They should be here by now.
(3)should + have done. 表示本来应该做的事情实际上未做。有责备之意。如：You should have given him more help.
(4) 表示惊讶，愤怒，不满，失望，遗憾或意想不到等情感。译为“居然，竟然”
如：I am sorry that he should be so rude.
I am surprised that he should be a thief.
注：should
是shall的过去式。
5、will的基本用法
(1)用于各人称，可以表示“意愿。意志”或“决心，打算”可用于各种人称。如：I will go with you.
He won’t listen to you because he is stubborn.
(2)在疑问句中用于第二人称，表示说话人向对方提出请求或询问对方的意愿，如：Will you please tell me how to get to the Great Wall?
(3)will可以表示一种习惯性的动作，有“总是,经常”之意，如：Every morning he will have a walk along this river.
6、would的基本用法
(1)would作为will的过去式，可用于各人称，表示过去时间的“意志”或“决心”，如：He promised he would never smoke again.
(2)在疑问句中，用于第二人称，表示说话人向对方提出请求或许问对方的意愿时，比用will的气更加婉转，如：Would you like some more coffee?
(3)在日常生活中，学用“I would like to…”表示“我想要”或“我愿意”之意，以使语气婉转，如：I would like to do Ex.2 first.
(4)would可以表示过去的习惯动作，比used to正式，并没有“今昔对比”的含义。如：He would go to the shop while he were France.
7、must的基本用法
(1)must表示“必须”、“应该”之意，其否定式 must not，缩写形式为 mustn't，表示“不准”、“不许可”或“禁止”之意，如：We must study hard and make progress every day. You mustn't touch the fire.
(2)对以must提出的疑问句，如作否定回答时，要用needn't或用don't (doesn't) have to (不 必)来回答，而不用mustn't，因为mustn't表示的是“禁止”或“不许可”之意，如：---- Must we finish the work tomorrow? ---- No, you needn't (don't have to), but you must finish it in three days.
(3)在肯定句中must可以表示肯定的推测，表示“一定”或“必定”之意，如：---- Whose new bike can it be? ---- It must be Liu Dong's. I know his father has just bought him a new one.
(4) 表示“偏要，偏偏”。含有一种无可奈何的口气。
The car must break down just when we were about to start off.
8、can, could, may, must后接完成式的用法
(1)can, could后接完成式(have done)的用法：①在否定句或疑问句中表示对过去发生过的事情的“怀疑”或“不肯定”的态度，Could he have said so? ②在肯定句中，可以表示过去本来可以做到的事而实际并没做到的事情，译为“本来可以…”。如：
-Did you visit the famous museum? –No,we could have visited it, but we spent too much time in shopping.
(2)may, might后接完成式(have done)的用法 ①表示对过去某事的没有把握的推测，译为“可能…”。如果使用might，语气就比较婉转或更加不肯定，如：Mary might have learned some Chinese before.
(3)must后接完成式（have done）的用法：表示对过去某事有把握的肯定推测，译为“一定…”，如：Liu Dong wasn’t in the classroom. He must have gone to the library.注：否定形式用can’t have done或couldn’t have done,译为“不可能”。不能用mustn’t.如：I saw him just now, and he can’t have gone on a travel.

情态动词练习
1.
3. Let's take a walk, ________?
A. will we B. don't we C. do we D. shall we
5. I went to the doctor's yesterday, I had to wait for half an hour before he ________ see me.
A. can B. may C. might D. could
6. - _____ this book be yours? ---- No, it is not mine.- It _____ be his.
A. Can, may B. May, must
C. Can, must D. Must, may
7. "We didn't see him at the lecture yesterday. " "He _________ it. "
A. mustn't attend B. can't have attended
C. would have not attended D. needed have attended
8. They _________ the plane, or perhaps they have been prevented from coming for some reason.
A. can have missed B. may have missed
C. can have lost D. may have lost
9. Since the ground is white, it _________ last night.
A. had snowed B. must have snowed
C. must be snowing D. must have been snowing
10. You must be fifty, ________?
A. mustn't you B. needn't you
C. aren't you D. isn't you
11. You must have seen him off yesterday, _________?
A. haven't you B. didn't you
C. mustn't you D. needn't you
12. - That must be a mistake. -No .it _____ be.
A. can't B. isn't able to
C. can D. was able to
13. He had known the matter before you told him, so you ____have told it to him.
A. mustn't B. can't C. needn't D. shouldn't
14. How ________ so?
A. dare you to say B. dare you say
C. do you dare say D. dare to say
15. You are their teacher. You ______care of them.
A. should to take B. might to take
C. ought to take D. need to take
16. She is studying medical science now but she _________ a lawyer.
A. used to be B. would be
C. were D. had been
17. If you were in an English-speaking country, you, _________ English every day ,too.
A. will be used to speak B. will be used to speaking
C. must be used to speak D. would be used to speaking
18. I did not call to make my airline reservation (预订) but I _________.
A. should have B. may have
C. must have D. shall have
20. Don't you remember that we _________ to the cinema tonight?
A. would go B. go C. are going D. will be gone
21. ---- Shall I tell John about it? ---- No, you _________. I've told him already.
A. needn't B. wouldn't C. mustn't D. shouldn't
22. "Would you mind if I open the window?" “__________”.
A. I don't like it B. Yes .please C. No, please not D. No. I'm sorry
25. "You ought to have come here ten minutes ago?" "Yes, I _________”
A. ought to B. ought to have C. ought D. have ought to
26. "Would you like to go out for a walk?" "Yes, ___________. "
A. I'd like to B. I'd like C. I'll like to D. I would
27. ________ you succeed !
A. Can B. May C. Must D. Will
28. Did he need ________ then?
A. leave B. to leave C. leaving D. left
29. Do you think if he dares _________ in public.
A. speak B. speaking C. to speak D. spoken
30. He ________ eating American food since he came here.
A. used to B. has been used C. has been used to D. was used to
31. A computer ________ think for itself; it ________ be told what to do.
A. may not, must B. mustn't, might C. shouldn't, could D. can't, must
32. "________ you mind my opening the window?" "Not at all. "
A. Shall B. Should C. Will D. Would
33.1 didn't hear the phone. I _________ asleep.
A. must be B. must have been C. should have been D. could have been
34. You _________ me about it earlier, but you didn't.
A. should have told B. would have told C. must have told D. should tell
35. The teacher told the students that they ________ keep silent in class all the time.
A. ought to not B. ought not to C. ought not to have D. can't
36. "May I go now?" "No, you ________. "
A. mustn't B. needn't C. mightn't D. won't
37. You _________ do the exercise if you don't want to.
A. may not B. can't C. mustn't D. needn't
38. You _________ pay more attention to your spelling next time.
A. would B. should C. will D. shall
39. The girl _________ out alone at night.
A. dare not go B. dare not to go C. dares not go D. does not dare go
40. There ________ be a lot of small houses on both sides of the street.
A. used to B. get used to C. would D. did use to

参考答案：
1~5 ABDDD 6~10 CBBBC 11~15 BACBC 16~20 ADAAC 21~25 ACBBB
26~30 ABBCC 31~35 DDBAB 36~40 ADBAA