情态动词用法归纳.doc

1、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, could1) 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

2、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(wont) be able to do this job this afternoon Ill not be able to come this afternoon.当表示“经过努

3、力才得以做成功某事”时应用be able to，不能用Can。如：He cant 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 cant.=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 ca

4、n. ( No, Im afraid not. )3) 表示客观可能性（客观原因形成的能力）。Theyve 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 cant 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

5、可用cant或mustnt，表示“不可以，禁止”。-Might/ May I smoke in this room? - No, you mustnt.- May/Might I take this book out of the room?- Yes, you can. (No, you cant / mustnt. )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。1He may /might be very b

6、usy now.2Your mother may /might not know the truth.三、 must, have to1) 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mustnt（禁止，不准），而用neednt, dont have to（不必）.- Must we hand in our exercise books today?- Yes, you must.- No, you dont have to / you neednt.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

7、时， have to 有更多的时态形式。1 he play isnt 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 Youre Toms good friend, so you must know what he likes best. 2 Your mother must be waiting for you now.四、 dare, need1) 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 dar

8、e you say Im unfair?2 He darent speak English before such a crowd, dare he?3 If we dared not go there that day， we couldnt 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。1You neednt come so early.2. - Need I finish the work today? - Yes, you must. / N

9、o, you neednt.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 doesnt dare (to) answer.3. He needs to finish his homework today. 五、 shall, should1) shall 用于第一人称，征求对方的意见。What shall we do this evening?2)

10、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 dont 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, would1) 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

11、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 oclock when she left home.七、 should, ought to1) should, ought to表示“应该”，ought to表示义务或责任，比should语气重。1.

12、 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

13、 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 didnt try your best. （虚拟语气）2. He

14、cant 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”

15、。其疑问、否定形式用can，cant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

16、/ should have helped him. (but you didnt.) 2. She shouldnt have taken away my measuring tape, for I wanted to use it.5) neednt +不定式完成式（have done） 表示“本来不必做而实际上做了某事”。 You neednt 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 arrive

17、d 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 cant be swimming in such weather.At the moment she may (might) be playing with her schoolmates.We neednt be standing here in the rain. We migh

18、t 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 couldnt have been swimming all day.情态动词部分练习题1) You_ all those clothes! We have a w

19、ashing machine to do that sort of thing A) neednt have washedB) shouldnt have washedC) must not have washed D) can not have washed2) Johns score on the test is the highest in the class; he_ last night.A) should study B) should have studiedC) must have studiedD) must have to study3) The room is in a

20、terrible mess; it _cleaned. (CET-4, 1996,6)A) cant have been B) shouldnt have been C) mustnt have been D) wouldnt have been4) 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 sailed5) Mary was

21、not in her bedroom yesterday afternoon. She _ in her classroom.A) should have been B) must have been C) must be D) should be6) Bob said he was going to join our club but he didnt. He _ his mind.A) cant have changedB) wouldnt have changed C) must have changed D) shouldnt have changed7) You_ to town t

22、o see the film yesterday. It will be on TV tonight.A) neednt go B) had better not go C) should not go D) neednt have gone8) We_ the letter yesterday, but it didnt arrive.A) must receive B) ought to receive C) must have received D) ought to have received9) With all the work on hand, he_ to the cinema

23、 last night.A) mustnt go B) shouldnt have gone C) could not go D) couldnt have gone10) 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 up11) I am feeling sick. I_ so much chocolate.A) neednt have eate B) couldnt have eaten C) mustnt hav

24、e eaten D) shouldnt have eaten12) I didnt send out my application form last week, but I _.A) had B) would doC) should have D) might have to13) Walking alone in the deserted village, John was scared. He thought he_ Tom to go with him.A) might have askedB) should askedC) must have asked D) should have

25、 asked14) When I got to the cinema, the film had already started; I_ there earlier.A) ought to getB) ought to have gotC) must have got D) must get15) The road was muddy. It_ last night.A) must rained B) must have rained C) must be rained D) could have rained16) She can speak quite fluent English. Sh

26、e_.A) must been in the U.S.A. for some time B) must have been in the U.S.A. for some timeC) 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 to18)“We di

27、dnt see him at the exhibition yesterday.”“He _it.”A) mustnt visit B) cant 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) Couldnt have received D) ought to have received20) I _ you a valuabl

28、e 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 give21)“Where _ my umbrella?”“Somebody _ it away by mistake.”A) is, must have taken B) is, must take C) have been, must take D) is, takes22) What _ would happen i

29、f the director knew you felt that way?A) will you suppose B) you suppose C) do you suppose D) you would suppose23) Two eyes _see more than one.A) can B) may C) will D) should24) _ you continue in your efforts and achieve new and greater successes.A) Would B) Will C) May D) Should 25) We ought to hel

30、p each other in our work, _?A) oughtnt we B) should we C) shouldnt we D) ought to we26) Tom _ better than to ask Dick for help.A) shall know B) shouldnt know C) has known D) should have known27) You _ your tooth pulled out before it rot completely.A) had better got B) had to get better C) had better

31、 to get D) had better get28) When we got to the cinema, the film hasnt started yet, so we _.A) neednt hurry B) didnt need hurry C) neednt to hurry D) neednt have hurried29) It was really very dangerous; you _ him seriously.A) might have injured B) could injure C) should have injured D) must injure 3

32、0) As he had heart attack, he was told that he _ continue the work.A) neednt B) may not C) mustnt D) cant31) An Englishman who _not speak Italian was once traveling in Italy.A) must B) could C) may D) might32) I _like to make a suggestion.A) could B) would C) must D) might33) I know things are hard

33、with you, but you _try to get over the difficulties.A) can B) may C) must D) ought34 I cant 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 away35) He _the 9:20 train because he didnt leave home till 9:25.A) can reach B) co

34、uld catch C) may not catch D) couldnt 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 . 单项选择 1.I thought you like something to read, so I have brought

35、you some books. A. may B. might C. could D. must 2. Youto the meeting this afternoon if you have something important to do. A. neednt to come B. dont need come C. dont need comingD. neednt come 3. He you more help, even though he was very busy. A. might have givenB. might give C. may have given D. m

36、ay 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 wasnt explained to us. A. had B. had to C. must D. might 6. I searched for my wallet and it wasnt there. I thought Iit at home. A. left B. have le

37、ft C. might have leftD. 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 fallenC. must have fallen D. mustnt have fallen 8. The only thing that really matters to the children is how soon they return to their sch

38、ool. A. can B. must C. have to D. ought to 9. I want to go to the chemists, 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. cant D. Coul

39、dnt 12.My goodness! Ive just missed the train. Thats 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 youve 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.

40、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 dont want to. A. havent B. cant C. mustnt D. neednt 17. Johnny, you play with the knife; you hurt yourself. A. wont; cant B. cant; sh

41、ouldnt C. shouldnt; must D. mustnt; may 18. Its nearly seven oclock. 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. cant be B. shouldnt be C. couldnt have been D. mustnt have b

42、een 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 its gone. It . A. must be stolen B. may be stolenC. must have stolen D

43、. must have been stolen 23. He the work yesterday, but he didnt. A. must have finished B. need have finishedC. finished D. should have finished 24. He did not pass the examination. As a good student, he . A. mustnt have failed B. may not have failedC. neednt have failed D. shouldnt 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. neednt B. mustnt C. wont