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, 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 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 can. ( No, I m 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 busy now. 2Your mother may /might not know the truth. 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 1 页，共 10 页2 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mustnt（禁止，不准） ，而用 neednt, 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。1How dare you say I m unfair? 2He daren t speak English before such a crowd, dare he? 3If 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。1You neednt come so early. 2. - Need I finish the work today? - Yes, you must. / No, 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, 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 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, would 1) 表示 请求、建议 等，would 更委婉。Will / Would you pass me the ball, please? 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 2 页，共 10 页3 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 oclock 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 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 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 ”精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 3 页，共 10 页4 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 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 couldnt 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) neednt have washedB) shouldnt have washedC) must not have washed D) can not have washed 2) 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 study 3) The room is in a terrible mess; it _cleaned. (CET-4, 1996,6) A) cant have been B) shouldnt have been C) mustnt have been D) wouldnt 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 sailedD) should have sailed 5) Mary was not in her bedroom yesterday afternoon. She _ in her classroom. A) should have been B) must have beenC) must be D) should be 6) 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 changed 7) You_ to town to see the film yesterday. It will be on TV tonight. 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 4 页，共 10 页5 A) neednt goB) had better not go C) should not goD) neednt have gone 8) We_ the letter yesterday, but it didnt arrive. A) must receiveB) 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) mustnt goB) shouldnt have gone C) could not goD) couldnt 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) neednt have eate B) couldnt have eaten C) mustnt have eaten D) shouldnt have eaten 12) I didnt send out my application form last week, but I _. A) had B) would doC) 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 askedB) should askedC) 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 getB) ought to have gotC) must have got D) must get 15) The road was muddy. It_ last night. A) must rainedB) must have rained C) must be rainedD) 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 timeD) 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 beC) was used toD) use to 18)“We didnt see him at the exhibition yesterday.”“He _it. ”A) mustnt visit B) cant have visited C) should have gone to seD) may see 19) Mary _my letter, otherwise she would have replied before now. A) should have receivedB) has received C) Couldnt have receivedD) ought to have received 20) I _ you a valuable present for your birthday, but I was short of money. A) would have liked to giveB) liked to give C) have liked to giveD) would like to give 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 5 页，共 10 页6 21)“Where _ my umbrella? ”“Somebody _ it away by mistake.”A) is, must have takenB) is, must takeC) 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 supposeC) do you suppose D) you would suppose 23) Two eyes _see more than one. A) canB) 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) oughtnt we B) should we C) shouldnt we D) ought to we 26) Tom _ better than to ask Dick for help. A) shall know B) shouldnt 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 hasnt started yet, so we _. A) neednt hurry B) didnt need hurry C) neednt to hurry D) neednt 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) neednt B) may not C) mustnt D) cant 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 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 away 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 6 页，共 10 页7 35) He _the 9:20 train because he didnt leave home till 9:25. A) can reach B) could 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 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. neednt to come B. dont need come C. dont need coming D. neednt 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 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 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. mustnt 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 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. Couldn t 12.My goodness! Ive just missed the train. 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 7 页，共 10 页8 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. 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; shouldnt 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 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 its 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 didnt. 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. mustnt have failed B. may not have failed C. 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 D. shouldnt 28. Her eyes were red. She . A. must cry B. must be cried C. must have been crying D. may cry 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 8 页，共 10 页9 29. Mary his letter, otherwise she would have replied before now. A. has receive B. must receive C. couldnt have received D. shouldnt have received 30. I told Sally how to get here, but perhaps I for her. A. had to write it out B. must have written it out C. should have written it out D. ought to write it out . 用所给动词的适当形式填空Hello. Gerry speaking. Hello, Gerry. Its me John here. Why arent you here at the meeting? Well, Im terribly sorry, but Im not feeling very well. Is that all? We thought you might (have) an accident or (forget) the day or something. No, Im sorry. I was sick all night. I think it must(be) the fish I ate last night. Well, I think you should at least (phone) Kate and (tell) her you werent coming to the meeting. Yes, I suppose I should (do) so. Im sorry about that. Anyway, I think Ill be able to get in to work tomorrow. OK, Take care and dont eat any more fish. I wont. Thanks for calling. Thats all right. 用 would, should, must , have to 填空1. I have not a raincoat with me. Thats why I wait until the rain stops. 2. you be so kind as to keep an eye on my house while I am away? 3. It is important that I see him at once. 4. the pain return，take one of these pills. 5. They didnt dare to leave the train lest they be attacked by wolves. 6. He ordered that Tom leave the house at once. 7. The last bus has left. We walk home. 8. The weather was bad. We wait for two hours at the airport before we took off. 9. You come and see us sometime. 10.The letter be translated into English. . 把下列句子译成英语1. 她一定把钥匙丢了. 2. 他们一定走了 , 可是应当给我留一个条子呀! 3. 你本不必要把整个课文都译成汉语. 4. 我是可能早一些来的, 可是我在路上碰到一个朋友. 5. 下一次你应该更小心些. 参考答案精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 9 页，共 10 页10 .1.B 2.D 3.A 4. C 5. B 6. C 7. C 8. A 9. A 10. B 11.C 12.A 13.C 14.A 15.C 16.D 17.D 18.D 19.C 20.A 21.D 22.D 23.D 24.D 25. C 26.B 27.A 28.C 29.C 30.C . have had; forgotten; be; have；honed; told; have done; . 1. have to 2. Would 3. should 4. Should 5. should 6. should 7. have to/will have to 8. had to 9. must 10. must .1. She must have lost her key. 2. The must have left, but they should have left us a note. 3. You neednt have translated the whole text into Chinese. 4. I could have arrived a little earlier, but I met a friend of mine on the way. 5. You should be more careful next time. 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 10 页，共 10 页