情态动词用法归纳.doc

情态动词用法归纳

情态动词有can (could), may (might), must, have to, shall (should, will (would), dare (dared), need (needed), ought to等。 情态动词无人称和数的变化；不能单独使用，必须与其后的动词原形构成谓语
一、 can, could
1) can, could表示能力（体力、知识、技能）。 Can you lift this heavy box?（体力）
Mary can speak three languages.（知识） Can you skate?（技能）
此时可用be able to代替。用be able to改写上面三个句子。Can只有一般现在时（can）和一般过去式（could）；
而be able to则有更多的时态。
am/is/are able to(一般现在时)：I am able to do this job,其它几个自己改写
was/were able to(一般过去式): He was able to do this job
will be able to(一般将来时)：I will(won’t) be able to do this job this afternoon
I’ll not be able to come this afternoon.
当表示“经过努力才得以做成功某事”时应用be able to，不能用Can。如：
He can’t swim,but he is able to cross the river.
2) can, could表示请求和允许。
-----Can I go now? =May I go now?
----- Yes, you can. / No, you can’t.=Yes,you may./No,you may not.
此时可与may互换。在疑问句中还可用could,
might代替，不是过去式，只是语气更委婉，不能用于肯定句和答语中。
---- Could I come to see you tomorrow?
---- Yes, you can. ( No, I’m afraid not. )
3) 表示客观可能性（客观原因形成的能力）。
They’ve changed the timetable, so we can go by bus instead.
This hall can hold 500 people at least.
4) 表示推测（惊讶、怀疑、不相信的态度），用于疑问句、否定句和感叹句中。
Can this be true? This can’t be done by him. How can this be true?
二、 may, might
1) 表示请求和允许。might比 may语气更委婉，而不是过去式。否定回答时可用can’t
或mustn’t，表示“不可以，禁止”。
----Might/ May I smoke in this room?
---- No, you mustn’t.
---- May/Might I take this book out of the room?
---- Yes, you can. (No, you can’t / mustn’t. )
用May I...？征徇对方许可时比较正式和客气，而用Can I...？在口语中更常见。
2）用于祈使句，表示祝愿。
May you succeed!
3) 表示推测、可能性（不用于疑问句）。
might不是过去式，它所表示的可能性比may小。
1．He may /might be very busy now.
2．Your mother may /might not know the truth.

三、 must, have to
1) 表示必须、必要。
You must come in time.
在回答引出的问句时，如果是否定的，不能用mustn’t（禁止，不准），而用needn’t, don’t have to（不必）.
---- Must we hand in our exercise books today?
---- Yes, you must.
---- No, you don’t have to / you needn’t.
2) must是说话人的主观看法， 而have to则强调客观需要。Must只有一般现在时， have to 有更多的时态形式。
1． he play isn’t interesting, I really must go now.
2． I had to work when I was your age.
3) 表示推测、可能性（只用于肯定的陈述句）
1． You’re Tom’s good friend, so you must know what he likes best.
2． Your mother must be waiting for you now.

四、 dare, need
1) dare作情态动词用时, 常用于疑问句、否定句和条件从句中, 过去式形式为dared。
1． How dare you say I’m unfair?
2． He daren’t speak English before such a crowd, dare he?
3． If we dared not go there that day， we couldn’t get the beautiful flowers.
2) need 作情态动词用时, 常用于疑问句、否定句。在肯定句中一般用must, have to, ought to, should代替。
1．You needn’t come so early.
2. ---- Need I finish the work today?
---- Yes, you must. / No, you needn’t.
3) dare和 need作实义动词用时， 有人称、时态和数的变化。在肯定句中，dare后面常接带to的不定式。在疑问句和否定句中，dare后面可接带to或不带to的不定式。而need后面只能接带to的不定式。
1. I dare to swim across this river.
2. He doesn’t dare (to) answer.
3. He needs to finish his homework today.

五、 shall, should
1) shall 用于第一人称，征求对方的意见。
What shall we do this evening?
2) shall 用于第二、三人称，表示说话人给对方的命令、警告、允诺或威胁。
1. You shall fail if you don’t work hard.(警告)
2. He shall have the book when I finish it.(允诺)
3. He shall be punished.(威胁)

六、 will, would
1) 表示请求、建议等，would更委婉。
Will / Would you pass me the ball, please?
2) 表示意志、愿望和决心。
1. I will never do that again.
2. They asked him if he would go abroad.
3) would表示过去反复发生的动作或某种倾向。would表示过去习惯时比used to正式，且没有“现已无此习惯”的含义。
1. During the vacation, he would visit me every other day.
2. The wound would not heal.
4) 表示估计和猜想。
It would be about ten o’clock when she left home.

七、 should, ought to
1) should, ought to表示“应该”，ought to表示义务或责任，比should语气重。
1. I should help her because she is in trouble. 2. You ought to take care of the baby.
2) 表示劝告、建议和命令。should, ought to可通用，但在疑问句中常用should。
1. You should / ought to go to class right away. 2. Should I open the window?
3) 表示推测 should , ought to (客观推测), must(主观推测)。
1.He must be home by now. (断定他已到家) 2.He ought to/should be home by now.(不太肯定)
3. This is where the oil must be.(直爽) 4. This is where the oil ought to/should be.(含蓄)
八、 情态动词+不定式完成式（have done）
1) can / could + have done在肯定句中表示“本来可以做而实际上能做某事”，是虚拟语气；在疑问句或否定句中表示对过去行为的怀疑或不肯定, 表示推测。
1. You could have done better, but you didn’t try your best. （虚拟语气）
2. He can’t have been to that town.（推测） 3. Can he have got the book?（推测）
2) may / might +不定式完成式（have done）
表示对过去行为的推测。不能用于疑问句中，没有虚拟语气的用法。Might所表示的可能性比may小。
1. He may not have finished the work . 2If we had taken the other road, we might have arrived earlier.
3）must +不定式完成式（have done）
用于肯定句中，表示对过去行为的推测。意为“一定、想必”。其疑问、否定形式用can，can’t代替。参看1) can / could + have done表示推测。
1. You must have seen the film Titanic . 2 He must have been to Shanghai.
4）should +不定式完成式（have done）
用于肯定句中，表示对过去行为的推测。 He should have finished the work by now。
表示“本应该做而实际上没有做某事”，其否定式表示某种行为本不该发生却发生了。可以与ought to +不定式完成式（have done）互换。
1. You ought to / should have helped him. (but you didn’t.)
2. She shouldn’t have taken away my measuring tape, for I wanted to use it.
5) needn’t +不定式完成式（have done）
表示“本来不必做而实际上做了某事”。 You needn’t have watered the flowers, for it is going to rain.
6) will +不定式完成式（have done）
主要用于第二、三人称，表示对已完成的动作或事态的推测。 He will have arrived by now
　情态动词也可以和动词进行形式或完成进行形式构成谓语：表示“应当正在……”，“想必正在……”的意思。
　　Why should we be sitting here doing nothing?
　　She might still be thinking about the question you raised.
　　He can't be swimming in such weather.
　　At the moment she may (might) be playing with her schoolmates.
　　We needn't be standing here in the rain. We might take shelter in the hut over there.
　　情态动词间或也可以和一个动词的完成进行形式构成谓语，表示“应当一直在……”，“想必一直在……”这类意思。
　　【例如】
　　They are sweating all over. They must have been working in the fields.
　　They may have been discussing the problem this morning.
　　She couldn't have been swimming all day.

情态动词部分练习题
　1) You____ all those clothes! We have a washing machine to do that sort of thing
　A) needn't have washed　B) shouldn't have washed　C) must not have washed D) can not have washed
　　2) John's score on the test is the highest in the class; he____ last night.
　　A) should study B) should have studied　C) must have studied　D) must have to study
　　3) The room is in a terrible mess; it ____cleaned. (CET-4, 1996,6)
　　A) can't have been B) shouldn't have been C) mustn't have been D) wouldn't have been
　　4) Nobody knows how people first came to these islands. They ____ from South America on rafts.
　　A) must have sailed B) can sail 　C) might have sailed　 D) should have sailed
　　5) Mary was not in her bedroom yesterday afternoon. She ____ in her classroom.
　　A) should have been B) must have been　 C) must be D) should be
　　6) Bob said he was going to join our club but he didn't. He ____ his mind.
　　A) can't have changed　B) wouldn't have changed C) must have changed D) shouldn't have changed
　　7) You____ to town to see the film yesterday. It will be on TV tonight.
　　A) needn't go　 B) had better not go C) should not go　 D) needn't have gone
　　8) We____ the letter yesterday, but it didn't arrive.
　　A) must receive　 B) ought to receive C) must have received 　D) ought to have received
　　9) With all the work on hand, he____ to the cinema last night.
　　A) mustn't go　 B) shouldn't have gone C) could not go　 D) couldn't have gone
　　10) Eve was late for class again. She ____earlier.
　　A) should get up B) must get up C) need to get up D) should have got up
　　11) I am feeling sick. I____ so much chocolate.
　　A) needn't have eate 　 B) couldn't have eaten 　C) mustn't have eaten D) shouldn't have eaten
　　12) I didn't send out my application form last week, but I ____.
　　A) had 　B) would do　C) should have D) might have to
　　13) Walking alone in the deserted village, John was scared. He thought he____ Tom to go with him.
　　A) might have asked　B) should asked　C) must have asked 　D) should have asked
　　14) When I got to the cinema, the film had already started; I____ there earlier.
　　A) ought to get　B) ought to have got　C) must have got D) must get
　　15) The road was muddy. It____ last night.
　　A) must rained　 B) must have rained 　C) must be rained　 D) could have rained
　　16) She can speak quite fluent English. She____.
　　A) must been in the U.S.A. for some time 　B) must have been in the U.S.A. for some time
　C) should have been in the U.S.A. for some time　 D) May be in the U.S.A. for some time
　　17) You should bear in mind that he is not so strong as he____.
　　A) was used to be 　 B) used to be　 C) was used to　 D) use to
　　18)“We didn't see him at the exhibition yesterday.”“He ___it.”
　　A) mustn't visit B) can't have visited C) should have gone to se　 D) may see
　　19) Mary ____my letter, otherwise she would have replied before now.
　　A) should have received　 B) has received C) Couldn't have received　 D) ought to have received
　　20) I ____ you a valuable present for your birthday, but I was short of money.
　　A) would have liked to give　 B) liked to give 　C) have liked to give　 D) would like to give
　　21)“Where ____ my umbrella?”“Somebody ____ it away by mistake.”
　　A) is, must have taken　 B) is, must take　 C) have been, must take D) is, takes
　　22) What ____ would happen if the director knew you felt that way?
　　A) will you suppose B) you suppose　 C) do you suppose 　D) you would suppose
　　23) Two eyes ____see more than one.
　　A) can　 B) may C) will D) should
　　24) ____ you continue in your efforts and achieve new and greater successes.
　　A) Would 　B) Will 　C) May D) Should
　　25) We ought to help each other in our work, ____?
　　A) oughtn't we 　B) should we 　C) shouldn't we 　D) ought to we
　　26) Tom ____ better than to ask Dick for help.
　　A) shall know 　B) shouldn't know C) has known 　D) should have known
　　27) You ____ your tooth pulled out before it rot completely.
　　A) had better got 　 B) had to get better 　C) had better to get 　D) had better get
　　28) When we got to the cinema, the film hasn't started yet, so we ____.
　　A) needn't hurry 　 B) didn't need hurry C) needn't to hurry 　D) needn't have hurried
　　29) It was really very dangerous; you ____ him seriously.
　　A) might have injured 　 B) could injure 　C) should have injured D) must injure
　　30) As he had heart attack, he was told that he ____ continue the work.
　　A) needn't B) may not 　 C) mustn't D) can't
　　31) An Englishman who ____not speak Italian was once traveling in Italy.
　　A) must 　 B) could 　C) may D) might
　　32) I ____like to make a suggestion.
　　A) could B) would C) must D) might
　　33) I know things are hard with you, but you ____try to get over the difficulties.
　　A) can 　B) may 　C) must D) ought
　　34 I can't find the recorder in the room. It ____ by somebody.
　　A) may have been taken away B) may leave C) may take away 　D) must have taken away
　　35) He ____the 9:20 train because he didn't leave home till 9:25.
　　A) can reach B) could catch 　　C) may not catch 　D) couldn't have caught
　　情态动词部分练习题答案
　　1)A 2)C 3)A 4)C 5)B 6)C 7)D 8)D 9)D 10)D
　　11)D 12)C 13)D 14)B 15)B 16)B 17)B 18)C 19)C 20)A
　　21)A 22)C 23)A 24)C 25)A 26)D 27)D 28)D 29)A 30)C
31)B 32)B 33)C 34)A 35)D

情态动词专项练习
Ⅰ. 单项选择
1.I thought you　　 like something to read, so I have brought you some books.[　 ]
　A. may　　 B. might　　 C. could　　 D. must
2. You　　to the meeting this afternoon if you have something important to do.[　 ]
　A. needn't to come B. don't need come C. don't need coming　D. needn't come
3. He　　　　 　you more help, even though he was very busy. [　 ]
　A. might have given　B. might give　 C. may have given　 D. may give
4.─　　　　　 　I help you with some shoes, madam?
　─ Yes, I would like to try on those brown ones. [　 ]
　A. Will　　 B. Should　　 C. May　　 D. Must
5. The reason why they 　　　　　　leave wasn't explained to us. [　 ]
　A. had　　 B. had to　　 C. must　　 D. might
6. I searched for my wallet and it wasn't there. I thought I　　　it at home. [　 ]
　A. left　　 B. have left C. might have left　　D. could have left
7. I asleep because it took me a long time to realize that the telephone was ringing.　[　 ]
　A. could have fallen B. should have fallen　
C. must have fallen D. mustn't have fallen
8. The only thing that really matters to the children is how soon they 　　　　　　return to their school. [　 ]
　A. can　　 B. must　　 C. have to　　 D. ought to
9. I want to go to the chemist's, but you 　　　　　　go with me.　 [　 ]
　A. need not　　 B. must not　　 C. need　　 D. must
10. I thought it over, but　　　　 come to no conclusion. [　 ]
　A. can　　 B. could　　 C. should　　 D. would
11. What we 　　　　　　get seems better than what we have. [　 ]
　A. can　　 B. could　　 C. can't　　 D. Couldn’t
12.─My goodness! I've just missed the train.
─That's too bad. I am sure you 　　　　　　it, if you had hurried. [　 ]
　A. could have caught 　 B. had caugh 　C. would catch 　　D. could catch
13. Look! What you've done! You 　　　　more careful.[　 ]
　A. may be B. had to C. should have been 　 D. would be
14. 　　　　　　I repeat the question? [　 ]
　A. Shall 　 B. Will 　 C. Do you want that 　 D. Do
15. Professor Li, many students want to see you. 　　they wait here or outside![　 ]
　A. Do　　 B. Will　　 C. Shall　　 D. Are
16. You 　　　　　　read that book if you don't want to. [　 ]
　A. haven't　　 B. can't　　 C. mustn't　　 D. needn't
17. Johnny, you　　　 play with the knife; you　　　　 hurt yourself.[　 ]
　A. won't; can't 　B. can't; shouldn't C. shouldn't; must 　D. mustn't; may
18. It's nearly seven o'clock. Jack　　　　 be here at any moment.　 [　 ]
　A. must　　 B. need　　 C. can　　 D. should
19. ─ There were already 5 people in the car, but they managed to take me as well.
─ It 　　　　a comfortable journey.　 [　 ]
　A. can't be　 　B. shouldn't be 　C. couldn't have been 　 D. mustn't have been
20. Tom ought not to 　　　　　　me your secret, but he meant no harm.[　 ]
　A. have told 　　 B. tell C. be telling 　 C. having told
21. Everyone is here. 　　　　　　we start the meeting? [　 ]
　A. Can　　 B. Must　　 C. Should　　 D. Shall
22. I parked my car right here but now it's gone. It 　　　　　.　[　 ]
　A. must be stolen　 　 B. may be stolen
　C. must have stolen 　 D. must have been stolen
23. He 　　　　the work yesterday, but he didn't.[　 ]
　A. must have finished　 B. need have finished
　C. finished　　　　　　 D. should have finished
24. He did not pass the examination. As a good student, he　　　　 .[　 ]
　A. mustn't have failed B. may not have failed
　C. needn't have failed D. shouldn't have failed
25. 　　　　it be true that Albert passed the test in geography? [　 ]
　A. May　　 B. should　　 C. Could　　 D. would
26. You 　　　　lead a horse to the water but you 　　　　　　not make it drink.[　 ]
　A. will; can 　 B. may; can 　C. may; dare 　 D. dare; can
27. ─Must we finish the composition in class?
─No, you 　　　　　.　[　 ]
　A. needn't 　 B. mustn't C. won't