精品资料欢迎下载情态动词情态动词是一种本身有一定的词义，但要与动词原形及其被动语态一起使用，给谓语动词增添情态色彩，表示说话人对有关行为或事物的态度和看法，认为其可能、应该或必要等。情态动词后面加动词原形。情态动词有四类：只做情态动词： must,can(could),may(might)可做情态动词又可做实义动词：need，will 具有情态动词特征： have(had,has) to,used to，ought to 情态动词表猜测：一肯一否三不定（must 一肯， can not 一否，may ，might ，could ，三不定。）注：mustnt代表强烈禁止 must 表示主观， have to 表示客观。常用的有： can may could must have use . 情态动词无人称和数的变化， 情态动词后面跟的动词须用原形，否定式构成是在情态动词后面加not 。个别情态动词有现在式和过去式两种形式，过去式用来表达更加客气，委婉的语气，时态性不强，可用于过去，现在或将来。情态动词属非及物动词，故没有被动语态。情态动词表推测的用法小结（一）情态动词表推测的三种句式1在肯定句中一般用must （一定）， can,could （可能）， might /may （也许，或许）。e.g:(1)He must/can/may,might know the answer to this question. 他一定 / 可能/ 也许知道这个问题的答案。(2)It is cold in the room. They must have turned off the heating. 屋里很冷，他们肯定把暖气关了。2否定句中用 cant / couldnt （不可能）， may not/might not（可能不）。e.g:(1)It cant/couldn t be the headmaster. He has gone to America.这不可能是校长，他去美国了。(2)He may not/might not know the scientist. 他也许不认识那位科学家。3疑问句中用 can/could （能 ?）。e.g:(1)Could he have finished the task? 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 1 页，共 6 页精品资料欢迎下载他可能把任务完成了吗？注：以上三种句式中情态动词的语气按程度都是依次递减的。Might,could并非 may,can 的过去式，而表示语气较为委婉或可能性较小。（二）情态动词表推测的三种时态1对将来情况的推测，用“情态动词 + 动词原形 ”。e.g:(1)She must / may / might / could arrive before 5. 5:00 前她一定 / 可能/ 也许到。2对现在或一般情况的推测，用“情态动词+ be”，“情态动词+be doing ”或“情态动词 + 动词原形”。e.g:(1)He must / may / might / could be listening to the radio now. 他一定 / 可能/ 也许正在听收音机。(2) He cant ( couldnt ) / may ( might ) not be at home at this time. 这个时候他不可能 / 可能不在家。3对过去情况的推测，用“情态动词 + have + 过去分词”。e.g:(1)It must / may / might / could have rained last night .The ground is wet. 地湿了，昨晚肯定 / 可能/ 也许下雨了。(2) The door was locked. He can ( could ) not / may ( might ) not have been at home . 门锁着，他不可能 / 可能不在家。注：情态动词 should /ought to表推测时，意为“想必会，理应”但与“have +过去分词”连用时，则又可构成虚拟语气意为“本应该做某事却没做”。例如：(4) It s seven o clock. Jack should/ought to be here at any moment. 现在七点钟了，杰克理应随时到达。（推测）（5）Tom should not /ought not to have told me your secret,but he meant no harm. （虚拟）汤姆本不该告诉我你的秘密，可是他并无恶意。can 和 could 表示推测的用法对现在或将来的推测，两者均可用，但can 通常只用于否定句或疑问句中，一般不用于肯定句，而could 则可用于肯定句、否定句和疑问句；对过去的推测，应在 can,could 之后接动词的完成式，且此时 can 仍只用于否定句或疑问句，不用于肯定句；而could 则可用于各种句型。如：精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 2 页，共 6 页精品资料欢迎下载Can Could this be true? 这能是真的吗Where can could he have gone? 他能到哪里去了呢She cant couldnt have left so soon. 她不可能走得这么早。注：could 后接动词的完成式，除表示对过去的推测外，还可表示过去没有实现的可能性（即某事本来可以发生，却没发生），或委婉地责备某人过去应该做某事而没有去做（此时不用can）。如：You could have started a little earlier. 你本可早点动身的。You neednt have cooked it. We could have eaten it raw. 你其实可以不煮熟（它），我们（本来）可以生吃。can 和 could 表示允许的用法表示现在的允许时，若是请求别人允许自己做某事，两者均可用，但用could 语气更委婉；若是自己允许别人做某事，一般只用 can ，而不用 could 。如：Can Could I come in? 我可以进来吗“Could Can I use your pen? ” “Yes,of course you can.” “我可以借用你的钢笔吗 ?”“当然可以。”（不能说Yes,you could.) 表示过去的允许时，若表示过去一般性允许（即表示某人随时都可以做某事），用could ；若表示在过去某一特定情况下允许进行某一特定的活动，则不用 could 。如：When I lived at home,I could watch TV whenever I wanted to. 我住在家里时，想什么时候看电影就可以什么时候看。（一般性允许）I was allowed to see the film yesterday evening. 昨天晚上允许我去看了电影。（特定的允许，不能用 could) can 和 could 表示能力的用法can 表示现在的能力， could 表示过去的能力， 要表示将来具备的能力通常 be able to 的将来时态。其中要注意的是， could 表示过去的能力， 通常只用于表示过去一般性能力，而不表示过去具体某次特定情形下能够做某事的能力。如：他学习很努力，所以考试能及格。误：He studied hard and could pass the exam. 正：He studied hard and was able to pass the exam. 注：若在否定句中没有以上限制，即couldn t 可表示过去特定情况下的能力，如可说 He studied hard but still couldnt pass the exam.口诀：情态动词两特点精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 3 页，共 6 页精品资料欢迎下载动词原形接后面， 说话语气较委婉。 can 能力may许可 ，must责任或义务 。否定回答 neednt换， 需要need, dare敢。should 应该，would 愿 ，have to 被迫表客观。情态动词专项练习题1. - Where is Mary? - She _ in the library. A. should be B. must be C. can be D. must have been 2. His room is dark. He must _ to bed. A. go B. be going C. have gone D. have been gone 3. “ Will your father stay home tonight?”“I m not sure, He _to work.”A. must go B. can go C. may be gone D. may be going 4. “ Where is Tom?” “ He isn t here I think he _ have gone home.”A. may B. must C. might D. A or B or C 5. “ I think Helen is at home.”“ No, she _ be at home, for she phoned me from the airport just five minutes ago.”A. mustn t B. needn t C. can t D. darent6. He s late. What _ have happened to him? A. can B. may C. should D, must 7. “ _ he be watching TV now?”Yes, he _ be watching TV now.”No, he _ be watching TV now.”A. Must; can; mustn t B. Can; must; cantC. Must; must; can t D. Can; can; mustnt8. “ _. He have left yesterday?”Yes, he _ yesterday.”No, he _ yesterday.”A. Must; must have left; can t have left B. Can; can have left; can t have left C. Can; must have left; can t have left D. May; must have left; shouldn t have left9. You must be a writer, _ you? A. mustn t B. areC. must D. arent10. You must have seen her yesterday, _ you? A. mustn t B. haventC. didn t D. don t11. You must have seen her, _ you? A. haven t B. didnt C. don t D. A or B12. There was plenty of time. She _ worried or hurried. A. mustn t have B. shouldn t have C. must be D. needn t have精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 4 页，共 6 页精品资料欢迎下载13. I got up early, but I _ so because I had no work to do that morning. A. mustn t have done B. didn t need to doC. needn t have done D. can t have done14. I _ up early this morning. So I stayed in bed till 9 a. m. A. needn t have got B. didn t need to getC. shouldn t have got D. can t have got15. The flower is dead. I _ it more water. A. will give B. would have given C. must give D. should have given 16. He _ have come here yesterday, but he didn t.A. could B. should C. ought to D. A or B or C 17. “ Must he do it?” “No, he _.”A. mustn t B. needn tC. doesn t have to D. B or C18. “ Need you go now?”“Yes, I _.” “ No, I _.”A. need; needn t B. must; neednt C. may; mustn t D. can; neednt19. “ May I borrow your bike?”“No, you _.”A. mustn t B. may notC. had better not D. can t20. “ Can I do it?”“No, you _.” or “ No, please _.”A. can t; doesn t B. can t; dontC. can t; can t D. can t; you dont21. I missed the last bus, so I _ go home on foot. A. must B. have to C. may D. had to 22. We _ hurry if we want to arrive in time. A. must B. need C. may D. have to 23. He ought to have won the first prize, _ he? A. oughtn t B. shouldnt C. mustn t D. oughtn t to24. He _ get up early when he lived in the countryside. A. would B. used to C. mustn t D. can t25. My brother _ be very naughty, and my sister _ like reading. A. used to; would B. would; used to C. used to; used to D. would; would 26. _ you please pass on a message to him? A. Do B. Shall C. May D. Will 27. _ we set off now? A. Shall B. Will C. Would D. ought 28. “ _ he open the window?”Yes, please.”A. Does B. will C. Shall D. Would 29. I ve told him many times, but he _ listen to my advice.精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 5 页，共 6 页精品资料欢迎下载A. shall not B. won tC. will not D. wouldnt30. “ Will you lend me a hand? ”“Yes, I _.”A. will B. shall C. can D. may 31. Everyone _ do his best for the modernization of China. A. will you B. don t weC. shall we D. do you 32. Let s clean our room, _?A. will you B. don t weC. shall we D. do you 33. Let us watch TV, _? A. will you B. don t weC. shall we D. do you 34. Close the door after you, _ you? A. don t B. doC. shall D. will 35. Every time he meets me, he _ to me. A. smiled B. would smile C. will smile D. is smiling 答案1-5 BCCDC 6-10 ABCDC 11-15 DDCBD 16-20 DDBDB 21-25 DDDDC 26-30 DACDA 31-35 CCADC 精选学习资料 - - - - - - - - - 名师归纳总结 - - - - - - -第 6 页，共 6 页