1、初中英语语法复习之情态动词专项【情态动词知识梳理】情态动词有具体的词义，但也同助动词一样，需要与其他词语一起构成句子的谓语，另外情态动词没有人称和数的变化，情态动词后必须跟动词原形。考点一：can，may，must 等情态动词在陈述句中的用法：1. can 的用法：（1）.表示能力、许可、可能性。表示能力时一般译为“能、会”，即有种能力，尤其是生来具备的能力，此时 may 和 must 均不可代替它。如：She can swim fast, but I cant . （2）.表示许可，常在口语中。如：You can use my dictionary. （3）.表示推测，意为“可能”，常用于否
2、定句和疑问句中，此时 cant 译为“不可能”。如：Can the news be true?No, it cant be our teacher. He is on a visit to the Great Wall.2. could 的用法：（1）.can 的过去式，意为“能、会”，表示过去的能力。如：He could write poems when he was 10. （2）. could 在疑问句中，表示委婉的语气，此时 could 没有过去式的意思。如:Could you do me a favour?Could I use your pen?Yes, you can.（注意回答
3、）3. may 的用法：（1）.表示请求、许可，比 can 正式，如：May I borrow your bike? You may go home now.(2) .表示推测，谈论可能性，意为“可能，或许”，一般用于肯定句中。如：It may rain tomorrow . She may be at home.(3) .may 的过去式为 might，表示推测时。可能性低于 may。如：He is away from school. He might be sick.(4) . 表示希望、祈求、祝愿，常可译为“祝愿” 。通常是用 may +主+V 例如：May you have a goo
4、d time. May you be happy! May you succeed！4. must 的用法：(1).must 表示主观看法，意为“必须、一定” 。如：You must stay here until I come back. Must I hand in my homework right now?(2)其否定形式 mustnt 表示“一定不要” “千万别” “禁止,不许”.如：You mustnt play with fire. You mustnt be late.（3）对 must 引导的疑问句，肯定回答为 must，否定回答为 neednt 或 dont have to
5、 .如： Must I finish my homework?No, you neednt.(4)must 表示有把握的推测，用于肯定句。如: The light is on, so he must be at home now.注意其反意问句的构成形式：当 must 表示肯定的判断、推测时，其反意疑问句要用实际问句的助动词来构成。如：She must have seen the film before，hasntshe?( 注意反意疑问句的后半部分 )You must have met uncle Wang in the shop yesterday，didnt you? (注意反意疑问句的
6、后半部分)5. need 的用法：（1）.need 表示需要、必须，主要用于否定句和疑问句中，其否定形式为 neednt，意为“没有必要，不必”。用 need 提问时，肯定回答为 must，否定回答为 neednt 或 dont have to。如： Need I stay here any longer?Yes, you must .No. you neednt /dont have to.(2).need 还可以作实义动词，此时有人称、数和时态的变化，如果是人作主语后边多接动词不定式。如：I need to do it right now. 如果是物作主语，一般用 need doing 与
7、 need to be done 这种情况下应注意两点：.主动形式的动名词 doing 具有被动的含义； .该动名词可以改为其动词不定式的被动形式而句子的意义不变。例如：. The door needs painting. = The door needs to be painted. 6. dare 的用法：dare 意为“ 敢、敢于”,用法近似于 need，有两种词性：（1）dare 作为情态动词，多用于否定句、疑问句或条件句中，无第三人称单数形式，只有一般现在时和一般过去时。如：Dare he tell them what he knows? I darent ask her will
8、you do it for me?（2）dare 作为实义动词，此时有人称、数及时态的变化。如： He doesnt dare to break his promise. 注意：口语中，dare 的各种形式常与不带 to 的不定式连用。如：Do you dare tell her what I said?7. shall 的用法：shall 表示征求对方意见（多用于第一、三人称） ，如：Shall we go out for a walk?8. should 的用法：（1）.should 意为“ 应该”，可表示劝告、建议、义务、责任等。如：We should protect the envir
9、onment.（2）Should have done 表示对过去动作的责备、批评。如：You should have finished your homework.9. will 的用法：will 表示意愿、意志、打算，可用于多种人称。如：I will help you if Im free this afternoon.10. had better 的用法：had better 意为“最好”，没有人称的变化，后面接不带 to 的不定式，其否定形式为：had better not。如：We had better go now.考点二：含有情态动词的疑问句的回答:1.对 may 引出的问句，可以
10、有下列回答方式：Yes,you may. Yes, of course. Yes, certainly. Sure . No, you mustnt. No, you cant.2.对 must 引出的疑问句，回答方式为：Yes, must. No, neednt/ dont have to.3.could 在疑问句中，表示委婉的语气，此时 could 没有过去式的意思。如:Could you do me a favour?Could I use your pen?Yes, you can.（注意回答）4. shall 引出的疑问句用于第一人称，表示征求对方意见或客气的请求。其回答方式有以下几
11、种： Yes, please. All right. No, thank you.5.would you的回答方式有以下几种：Yes, I will. (No, I wont.) Sure . (Im sorry , I cant.) All right/ OK/ With pleasure. Certainly. (No, thank you .) Yes, please.考点三:不同情态动词的否定意义也不同：1.（1）.cant 可译为“ 不会” ，如：I cant play basketball.（2）当句子表推测时，用 cant 表达不可能，如：He cant be ill. He i
12、s playing chess with Tom.（3）cant 还可用来回答“ May I ? ”这样的问句。如：May I come in ? No, you mustnt. / cant.（4）cant 还可用于固定习语中。cant help doing 禁不住，情不自禁 cant wait to do something 迫不及待地要做2. may 的否定式为 may not，译成“可能不”，如：He may not be at home.3.（1）mustnt 表示不许，不可。如：He mustnt leave his room.(2) mustnt 也可用于以 may 表示要求时的
13、否定回答中。如： May I stand here?No, you mustnt (cant).4.（1）neednt 意为“ 不必” 。如：You neednt meet him unless youd like to.（2）neednt + have+动词的过去分词，表不需要完成但已完成的动作，暗含时间或精力上的浪费。如： You neednt have bought it.你没必要买它（但你却买了） 。5. shouldnt 表示不应该。如： You shouldnt feel so unhappy over such little things.考点四:情态动词的被动语态含有情态动词的
14、被动语态的结构为：情态动词+ be + done (动词的过去分词)。做题时要兼顾情态动词和被动语态这两个方面。考点五:情态动词表示推测的用法:一、 “情态动词+动词原形”表示对现在的推测。1、can 表示推测时一般用于否定句或疑问句。如：That man cant be her husbandshe is still single.2、must 表示肯定的推测，一般用于肯定句中。如：He must be in his office now.3、might 表示推测时不一定是 may 的过去时，只是表示其可能性较小。如： The man may be the headmaster.4、Coul
15、d 表示推测时，语气 can 比要弱，说话者留有余地。如： Could it be an animal?It could not be，because it is not moving.5、Should 表示推测的可能性比较大，仅比 must 的可能性小一点。如： It is already 10 oclock now they should be there.二、情态动词表示对过去可能发生的动作或存在过的动作的推测性用法。1、 “must +have done/been-”表示“过去一定发生过某事或存在过某种状态” ，不用于“musnt+have-”形式。如：She must have se
16、en the film before，hasntshe?(注意反意疑问句的后半部分)2、 “should +have done /been-”表示“本应当做某事，而实际上并没有做 ”；“shouldnt+ 完成式”表示“本来不应当做，而实际上却做了” 。以上结构常带有说话者的责备的感情色彩。如：You should have finished your homework earlier (but in fact you did not finish it on time).3、 “neednt+完成式”表示“本来没有必要做某事，而实际上却做了” 。如：There was plenty of t
17、ime. She neednt have hurried .4、 “cant /couldnt+have done /been-”表示“过去不可能发生了某事或存在过某种状态” 。如：I saw him just now. He cant have gone to Japan.5、 “could+have done/been-”表示“过去本来能够，可以做某事或成为某种状态，而实际上没有” ，说话者有些遗憾。6、 “may/might+完成式”表示“过去可能，本来可以于某事而实际上没有干” ，might 的可能性较小，语气较弱。如：He may have finished reading the
18、book. 【情态动词易混点归纳】易混点一: can 和 be able to:两者表示能力时用法相同，但 can 只有原形“can”和过去式“could”两种形式，在其他时态中要用 be able to 来表示。另外 be able to 常常指经过努力，花费了时间和劳力之后才能做到某事。易混点二:can 和 may1. can 和 may 均可用来征求意见或许可，意为 “可以” ，一般可互换使用。如：Can/ May I help you ? 我能帮助你吗？ 2. can 和 may 表示可能性时的区别：1)在肯定句中用 might，may ，must，不用 can2)在疑问句中表示推测用
19、 can，不用 might，may ，must3)在否定句中用 cant（不可能） ，不用 may，must。如： She may be in the classroom .她可能在教室里。Where can they be now?他们现在可能在哪儿？That cant be true.那不可能是真的。易混点三: may be 和 maybe用法区别 常用位置may be may 为情态动词， be 为动词原形 句中，作谓语maybe 副词，大概、也许，相当于 perhaps 句首，作状语例如：He may be wrong , but Im not sure.也许他错了，但我也不确定。易混
20、点四：cant 和 mustnt1. cant 根据其基本用法可译为：（1）不会。如：I cant speak English .我不会说英语。（2）不能。如：We cant do it now because its too dark.天太黑了，我们现在干不了。（3）否定句中表示推测。 “不可能”，如：The man cant be our teacher because he is much younger than our teacher。2. mustnt 意为“禁止、不许”，用来表达命令，表示强烈的语气。如：You mustnt play football in the street
21、. Its too dangerous.易混点五：must 和 have to1.must 侧重于个人意志和主观上的必要。have to 侧重于客观上的必要，可用于现在时、过去时和将来时。易混点六: used to do / be used to doing / be used to do/ be used for doing sthused to do 表示过去常常发生的动作，强调过去，只用于过去；而 be used to doing 意为“习惯做” ；be used to do 意为“被使用去做,”为被动语态形式。be used for doing sth“用作”1. _ I go out
22、 to play now，Mum? No，you_ AMay，shouldnt BCan，neednt CMust ，cant DMaymustnt2. Help me with this case_ you? Adont Bwill Cdo Dshall3. They started early that morning in order that they_ there before noon Amight get Bmay get Cwould get Dgot 4. A teacher do every exercise，but a pupil_ Aneednt，must Bmay n
23、ot，must Cneednt, neednt Dcant, must5. If you _ do as I tell you，you_ go to the party Acan，shant Bwill, wont Cwont，shall D wont, shant 6. Could it be an animal? It _ not be.Acan Bwill Ccould D may7. Dont believe himHis story _ be true Amustnt Bneednt Cshouldnt Dmay not8. -She must have gone back to t
24、he valley -No, she _ . The entrance to it was nowhere to be foundAmustnt Bneednt Ccouldnt Dhadnt 9. You need not do it at once,_? Aneednt you Bmustnt you Cdont you Dneed you10. He must be in the classroom_ he? Amustnt Bcant Cisnt DCan11. Lets go to the libraryshall we? _ ANo，I cant BYesI will CYes ，
25、thank you DNo，Wed better not12. You ought to have called him yesterday Yes, I know I_Aought to Bought to have Cought to have done Dought to have called13. -Why did you keep it a secret from me? -I _ about itAshould be told Bought to have been told Cshould have told Dought to be told14. The work _ be
26、 finished in such a short time Awasnt able to Bcouldnt Cought Dcould15. He looks very tiredHe _ to bed too late last night Amust go Bmust have gone Ccould go Ddidnt go16. The door _ lock Acant Bmay not Cwont Dmustnt17. As a soldier，you _ do as the head tells you Awill Bshall Cmay Dought18. How _ you
27、 be so careless? Acan Bwill Ccould Dmay 19. I talked for a long time，and in the end I_ make her believe me Acould Bcan Cmust Dwas able to20. Did you scold him for carelessness ? Yes，but _ it AId rather not do BId rather not have done CI shouldnt do DId better not do21. He neednt come to attend the m
28、eeting_ ?Adidnt he Bdoesnt he Cneed he Dmust he22. Fish _ die without water Awill Bshould Cshall Dmust23. Wed better hurryOur teacher _ us Await for Bmust wait for Cmust be waiting for Dhas waited for24. I saw him leave the room an hour agoHe _ at this time Amustnt be working Bcant be working Ccant
29、work Dmay not being working25. _ basketball every day? ADid you used to playing BDid you use to play CUse you to play DUsed you play26. Why_ you keep on troubling me with such questions while I am busy ? Acould Bcan Cmust Dwill27. -You were driving at 100km an hour, sir -But officer，I_ ，my car cant
30、go more than 90. Amay not have been Bcouldnt have been Cwould have been Dneednt have been28. You _ call him if you want to，but you_ ，for hell surely come here soon Acan，neednt Bmay, mustnt Chave to ，neednt Dcan, doesnt need29. At last he _ finish the work ahead of time Acould Bwas able to Ccould hav
31、e done Dwould have been able to30. There must be some enemy soldiers in the forest._ any behind the church? AMust there be BShould there be CMay there be DCan there be31. The shy girl_ dance before so many strangers， _she?Adarent ，does Bdarent，dare Cdoesnt ，dare Ddare notDares32. “When _ he leave th
32、e hospital?” I asked the doctor Awill Bshall Ccan Dmay 33. -They havent finished the work up to now -Well， they_.Ashould have Bshould Cought to Dought have34. The money was soon spent，so she _ go hungry Amust Bhad to Cmight DShould35. Jack studied hard and _ pass the examination Acould able to Bwoul
33、d Cwas able to Dought36. You dont look well，you _ have a fever Amight Bcan Cshall Dshould37. You are running a fever，you _ to see the doctor Aneed go Bmust have gone Cshould go Dcan go38. I _ take the jobNo one _ stop me Awill，can Bcan，must Cmust，can Dwill, must39. There used to be a high tower here
34、，_ ? Awas there Bwasnt there Cused there Dusednt there40. Whenever the teacher was not there, the children _ make a lot of noise Awill Bwould Cwere to Dwere going to41. He must be shy, _ he? A must Bmustnt Cis Disnt42. I must do it, _ I? Ado Bdont Cmust Dmustnt43. You did not go to the party yesterd
35、ay, or I _ you. Awould see Bcould meet Cmight have seen Dmight see44. -How do you like the food here? -Oh， excellent! We _ a better hotel Acant find Bwont find Cmustnt have found Dcouldnt have found45. -We were waiting for you this time yesterday -Sorry，I _ you to tell you that I couldnt come.Amust
36、have called Bwould have been calling Ccould have been calling Dshould have called46. -Would you mind returning the book tomorrow? -_AOk，I will BSure, I wouldnt CYes ，I wouldnt DWhy, I wouldnt47. See whos there! _ it be Mary? AMay BMust CCan DWill48. My little son _ out a1one at night Adares not go B
37、dares not to go Cdare not to go Ddoesnt dare to go49. You _ miss seeing so good a film，it is one of the best films Ive ever seen Ahad better not to Bhave better not to Chad better to not Dhad better not50. It is strange that she _ so A. think Bthinks Cwill think Dthought51. _ you rather sit at the b
38、ack? AWont BWouldnt CDont DWill52. -Where_? -She _ to school, for it is Sunday today Acan she go，cant go B. may be go，may not go Ccan she have gone, cant have gone Dcan she go，cant have gone53. Since she is angry, we _ Ahad better to leave her alone Bshould leave her alone Cmight as well leave her a
39、lone Dmust leave her alone54. -Do you think he will do me a favour? -Its very unlikely，but he _ be prepared to help you Amust Bwill Ccan DMight55. Will you sing a song at the party? No, I_ Awouldnt Bwont Cshouldnt Dshall not56. My brother used to get up early in the morning，but my sister seldom _. A
40、. used to B. did C. used D. both A and B57. -Will it be raining this afternoon? -No，Im afraid it_Amay not Bwont Cmustnt Dshouldnt58. You _ in such a hurry，Ill have the car waiting for you Adont need being Bdont have been Cneed not to be Dneednt be59. I have kept the book for 3 weeksI _ them to the library last week Aought return Bought to return Cought have returned Dought to have returned60. -_ I get you some food? -NothanksA. Might B. Shall C. Will D. Ought
