情态动词表推测的讲解及练习题

1、键入文字九年级英语表推测语气的讲解与练习表推测时，英语中只使用 must,may,might,may no和 cant。这五个表达的语气依次递减：must: 一定（语气肯定）may :也许（不很肯定）might:或许（比 may 语气更弱）may not:也许不（表否定）cant: 定不（must的反义）推测现在的事情用 must,may,might,may not和 cant+do 或 bee.g.She must be at home now.The boy may play now.推测过去的事情用 must,may,might,may not和 cant+have donee.g.Sh

2、e might have bee n ill yesterday.He must have hold the party.情态动词 must, can, could, may, migh表推测的用法情态动词中的 must, can, could, may, migh诸E表推测。其中 must的可能性最大，can / could次之，may / might最小。具体用法如下：1. must的用法（1）表示推测可能性”时，意思是一定、准是”，语气较肯定，较有把握。He must be America n. = It is certa in that he is America n.他准是个美国人。

3、（2） must表推测只能用于肯定句。如果要表示一定不、肯定不”的意思时，应 用can如询问某种可能时，应用can。He must kn ow my address.他肯定知道我的地址。（一定）He can t know my addres他肯定不知道我的地址。（一定不）Can he know my address?他知道我的地址吗？（询问可能性）（3）must表示推测时，可以推测现在/正在发生的动作/过去发生的动作。He must have a car now.（现在）他一定有辆小汽车。He must be doing his exercises in the classroom.正在进行）

4、他一定在教室里做练 习。He must have finished the work.（过去发生）他一定已完成了工作。注：must表示推测时很少用于将来的情况。一般不用He must come tomorrow可用 Its certain / I m sure that he will come tomorrow.（4） 在反意疑问句中，当附属部分含有表示推测意义的must时，疑问部分的助 动词应与must后面的动词在非推测情况下的用法保持一致。He must be a worker, isn（现在？他准是个工人，是吗？It must have rained last night, didn（

5、过去 昨t晚一定下雨了，是不是？You must havelear ned En glish for many years, have n（完成时？你一定学了好多年英语，是吗？2. ca n / could 的用法（1） can表示推测 可能性”时，往往用于否定句或疑问句。Can t一定不”语 气很肯定。can在疑问句中意思是 会、可能”用于肯定句时，表示理论上的， 潜在的可能性（有倾向，实际上未必会发生或者不涉及实际是否发生）往往与 sometimes 或者 some one 有关。Accide nts can happe n.He can t behrime. = It is imposs

6、ible that he is at home.他一定不在家。（2）can /can后可接进行时/完成时，表示对现在发生的动作或过去发生的动作 进行推测。They can t be reading in the libra他们一定不在图书馆读书。He can t have gone to Shanghai for I saw him a minute ago.他不可能去了上海，我刚才还看见他。It s so late. Where cae save gone?天晚了，她可能去哪儿了呢？（3）在反意疑问句中，当陈述部分含有表示推测意义的can时，疑问部分的助 动词应与can后面的动词在非推测情况

7、下的用法保持一致.He can t be a teacher, is h他不是教师，是吗？She can t have finished her homework, has sh她一定没有完成家庭作业，是不 是？could可用于表示某事有可能发生表示可能性不大的推测。意思相当于may/mightDon t eat .itIt could be poisonous.不要吃它，可能有毒。The pla ne could be delayed by fog.飞机可能会因为雾晚点。（5）could还可以用于表示客气、委婉、礼貌的请求语气。Excuse me, could you tell me the

8、 way to the bus stati on?Could you help me?（6） couldn 表示否定推测，表示某事不可能真实，或由于特定事实或环境某事 肯定不会发生。It couldn t posbb poison.这不可能是毒药。表示对过去发生的事推测，常常和 have do ne连用He was not at home last ni ght . He could/ might have gone to movies.I did nt see her at the meet ing yesterday; she could nt have spoke n at the me

9、et ing.3. may和might的用法（1）may, might表示推测 可能性”时，意思是 可能” 也许”语气没有mustHe may / might be America n. = It is possible that he is America n.他可能是个美国人。注：might不表示过去时态，只是语气上比may更委婉，表示的可能性更小。（2）may, might表推测时，可以用于否定句，意思是 可能不、也许不”但不 用于疑问句。He may / might not be at home.他也许不在家。（3）may, might可以推测现在正在发生的动作或过去发生的动作。He

10、may / might be sleeping now.（现在）他可能正在睡觉。The boy may / might not be watching TV at home.（现在）这个男孩可能没在家看电视These stude nts may / might have see n the film before.过去） 这些学生以前可能看过这部电影。（4）may, might还可以推测将来的情况。I think we should take rain coat with us, it may rain.我想我们应该带上雨衣，可能要下雨了。She might not come this aft

11、er noon.她今天下午可能不来（一）情态动词表推测的三种句丄能用于表推测的情态动词： must, can, could, will, would, may, might, should, ought to1. 在肯定句中一般用 must （一定），may（可能），might / could （也许，或许）（1）He must/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

12、肯定把暖气关了。2. 否定句中用 can t / couldn t（不可能）,may not/might not（ 可能不）。（1）It can t/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,?）。（1） Could he have finished the task?他可能把任务完成了吗？（2） Can he be at home now?他现在能在家吗

13、？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1. 对将来情况的推测，用 “情态动词+动词原形(1) She must / may / might / could arrive before 5.5:00 前她一定 / 可能 / 也许到。(2)She must/may/might/couldwalk miles and miles amongthe hills without meeting4键入文字anyone.她一定/可能/也许会在山里一连走好几英里而遇不到一个人。2

14、.对现在或一般情况的推测，用情态动词+ be ” ， “情态动词+be5键入文字#键入文字doing ”或“情态动词+动词原形”(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 can t ( couldn t ) / may ( might ) not be at home at this time.这个时候他不可能/可能不在家。(3) Mr. Bush is on time for everything.How can ( could ) he be late for

15、 the opening ceremony ?布什先生一向准时，这次开幕式他怎么可能迟到呢？3.对过去情况的推测，用“情态动词+ have +过去分词（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。（3）Can / Could he have gotten th

16、e book？ 难道他找到书了吗？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 tobe here at any moment.现在七点钟了，杰克理应随时到达。（推测）（5）She should / ought to have atte nded your birthday party, but she had to lookafter her mother in hospital.（虚拟）她本该出席你

17、的生日晚会的，可是她得在医院照顾她妈妈。（6）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。补充强调：推测的句型特点（对某一次的推测句型有两部分：语气和时态）（1） 语气部分：（以下情态动词语气由强至弱）肯定句：must、may might （ =could）否定句：can t （ =couldn t）、mayn t、mightn t 疑问句：can、could （语气更加委婉不确定）（2）时态部分：be 表示对现在的推测 have don

18、e 表示对过去的推测be doing表示对正在进行的推测语气部分写在前时态部分写在后，组合在一起就是推测（三）几组表推测的情态动词用法情态动词+完成时”是历年高考的热点，在做此类练习时，既需要掌握这一结构的基本 用法，又应该仔细体会题干所提供的语言信息，准确理解语言环境和说话人的含义，尤其要注意题干中时态给予的暗示。定，想必”，句子中表示的是- can t(couldn )thave donel.must have done表示对已经发生的事情的推测，意为 种肯定的推测。这种结构一般只用于肯定句，其否定形式是 表示 不可能，肯定不会。例如：He didn t hear the phone .

19、He must have been asleep. 他没有听到电话响，他肯定是已经睡着了。He must have bee n to Shan ghai.他一定去过上海。They can t have gone out , because the light is or他们不可能出去，因为灯亮着。2. can (could) have done表示对过去的时间内可能发生的事情的猜测，can have done般只用于否定句和疑问句。could have done还可以用于肯定句，常用来表示本来可能完成而实际未完成的动作。例如：He can t have finished the work so

20、 soon这项工作他不可能完成得这样快。We could have walked to the station , it was so near .我们本来是可以走到车站去的，路很近。3. may (might) have done(1)表示对已经发生的事情的不太肯定的推测，意为可能已经，或许已经”。(2 )虚拟用法表示本可以做，但却没做(表示很委屈地责备)If we had taken the other road , we might have arrived earlier. 如果我们选择另一条路，我们可能会到得早一些。He might have give n you more help

21、, he was very busy.他本来是可以给你更多帮助的，尽管他很忙。4. needn t have do指实际上做了本来不必要做的事，意为本来不必”。例如：There was plenty of time . She needn t have hurried.时间很充裕，她本不必匆忙。You needn t have told him the news.他本来不必把这个消息告诉他。5. should (ought to ) have done指本该做而实际未做的事，意为本来应该”。其否定式shouldn (oughtn )thave done则表示某种行为不该发生但却发生了。例如：Y

22、ou should have started earlier , but you didn t.你本应该早一点出发，但是你没有。You ought to have helped him(but you didn ) . t 你本应该帮助他。We shouldn t have waited for her because she never came.我们本不应该等她，因为她根本不会来。6. Would have done本想做(去卩没做)wouldnthave done本不想做(去卩做了)I would have helped you, but I was too busy.我本想帮你，但我太

23、忙了。小试牛刀一、单项选择1 Johncome to see us toni ght, but he isnt very sure yet.A. may B. need C. can t D. must2 John isn t in the classroom. He play soccer on the playground with Bob.A. can B. must C. should D. can t3 Thatnot be her husba nd . She is still sin gle.A. may B.ca n C. could D. might4 Yougo and s

24、ee a doctor at once because you got a fever.A. can B. must C. dare D. would5 -Ca n you speak Japa nese? -No, I.A. must ntB. cant C. n eed ntD. may not6 -Hebe in the classroom, I thi nk.-No, hebe in the classroom. I saw him go home a mi nute ago.A. can; may not B. must; may not C. may; cant D. may; m

25、ust nt7 -Is Lena swimming in the pool?-No, she swim. She is terrified of water.A. may not B. must notC. cantD. n eed nt8 He isnt at school. I think hebe ill.A. can B. shall9 -What do you think-I m not sure. ItC. must D. might “upsens? mea mea n sad .A.may B. must C. canD. should10 The childrenplay f

26、ootball on the road.A. cantB. can C. must ntD. mustThe road is wet . Itlast ni ght.9键入文字#键入文字A. must rainB. must have rained#键入文字C. could have rained D. can have rained12 .Heyou more help , eve n though he was busy .A might have give n B might not giveC may not have give nD may give练一练1. Look! The l

27、ight is out in her room. Sheto bed already.A. must go B. had to go C.must have gone D.has gone2. We had a won derful time yesterday. You.Why did nt you come?A. had to come B.should have come C.might have come D.must have come3. There were already five pdep n the car but they man aged to take me as w

28、ell.Ita comfortable journ ey.A. cant beB. should nt be C. must nt have bee n D. could nt have bee n4. My sister met him at the Grand Theatre yesterday after noon, so heyour lecture.A. could nt have atte ndedB. n eed nt have atte ndedC. must nt have atte ndedD. should nt have atte nded5. I was really

29、 an xious about you. Youhome without a word.A. must nt leaveB. Should nt have leftC. Could nt have leftD. need nt leave6. Oh, I m not feeling well in the stomach_o much fried chicken just now.A. shouldn t cutB.mustn t have eatenC. shouldn t have eatenD.mustn t eat7. Mr.Whiteat 8:30 for the meeting,

30、but he didn t show up.A. should have arrivedB.shouldarriveC. should have had arrivedD.shouldbe arriv ing8. Yoube tired - youve only bee n work ing for an hour.A. must notB. won tC. can tD. may not9. - Is n t that Anns husba nd over there?-No, itbe him -Im sure he does nt wear glasses.A. cantB. must

31、notC. wontD. may not10. Therebe any difficulty about pass ing the road test since you have practised alot in the driv ing school.A . mustn t B. shan tC. shouldn tD.needn t11. I was on the highway whe n this car went past followed by a police car. They at lease 150 km an hour.A. should have bee n doi

32、ngB. must have bee n doingC. could have doneD. would have done12. Hehave completed his work; otherwise, he wouldn t be enjoying himselfby the seaside.A. should B. must C. wouldn t D. can t13. - The woma n biologist stayed in Africa study ing wild ani mals for 13 yearsbefore she returned.- Oh, dear!

33、Shea lot of difficulties!A. may go throughB. might go throughC. ought to have gone throughD. must have gone through14. This cake is very sweet. Youa lot of sugar in it.A. should putB. could have put C. might put D. must have put15. Catheri ne, I have clea ned the room for you.Than ks. Youit. I could

34、 man age it myself.A. needn t do B. needn t have doneC. mustn t do D. shouldn t have done16. Tom is never late for work. Why is he absent today?Somethi ngto him.A. must happe nB . should have happe nedC . could have happe nedD . must have happe ned情态动词+have done结构1 . -You didn t wait for Mr. Smith l

35、ast night, did you?-No, but we. He didn t return home at all.A. couldn t have waitedB. needn t haveC. didn t need to D. should wait2. Harryhave won the Physics competition easily yesterday, but he gave up.A. could B. might C. should D. must3. -May I speak to your manager Mr. Smith at six o clock ton

36、ight ?”-“I m sorry, Mr. Smith to a conference before then.”A. will have gone B. had gone C. would have gone D. has gone4. -Tom took away our teacher s cell phone without being permitted.-Really? I can t imagat hehave done such a thing.A. must B. may C. can D. should6. The weather turned out to be fine yesterday. Ithe trouble to carry myumbrella with me .A. should have take n B. could have take nC. n eed nt have take n D. must nt have take n7. He paid for a seat, when hehave entered free.A. could B. would C. must D. n eed8. I didn t