情态动词讲解定义：情态动词表示说话人对动作的态度，比如：需要，可能，意愿，猜测或者怀疑等等。

情态动词本身有一定意思，但不完全，不能单独作谓语，必须与动词原形连用。

否定句中，在情态动词后面加not。

情态动词有：must, shall, should, had better 词形无变化can(could), may(might), will(would) 词形有变化need既可以是情态动词，也可以是实义动词，具有双重性。

一、can 表示“能，会”，否定为：can’t = can not = cannot其过去式为：could→couldn’t(1)表示会做某事，有能力做某事。

意思= be able toe.g. He can speak English, but he can’t speak Japanese.= He is able to speak English, but he isn’t able to speak Japanese.I could smile but I couldn’t speak w hen I was 2 months old.= I was able to smile but I wans’t able to speak when I was 2 months old.区别：① can只用于现在时和过去时(could), be able to 可用于各种时态。

e.g. They will be able to tell you the news soon.Mingming has been able to count numbers.② be able to 不与can连用，但可以和其他情态动词或助动词连用。

e.g. He may be able to speak English very well some day in the future.He may can speak…………………………………………………..He can be able to speak……………………………………………..(2)用于征求意见——Can /Could /May /Might I(we) do sth?——Yes, you can/may. / Of course you can.——No(Sorry), you can’t. /mustn’t.注意：①此处的could和might都不表示过去，只是语气上的委婉，不用作回答。

②否定回答中，表示对他人造成一定伤害或影响，或表示违反了某种规定或法律时，用mustn’t较好。

e.g. ——Could I take the book out of the library? ——Sorry, you mustn’t.——May I smoke here? ——I’m afraid you mustn’t.③表示过去能力时，could 提问，只能用could回答。

e.g. ——Could you ride a bike when you were 4 years old? ——No, I couldn’t.(3)表提出意见或请求Can/Could you (please) do sth? = Would you (please) do sth? （此句型中some 不变any）e.g. Could you please give me a hand?Would you please pass me some salt?(4) 表示允许或承诺=maye.g. OK. You can /may come and find me at any time tomorrow.(5) 表示有一定把握的推测，用于否定句和疑问句。

肯定句用must。

表示没有把握的推测，用may /might。

e.g. —— The window is broken. Who did it?—— It may be Mary.——It can’t be Mary. The window is in the men’s toilet.—— Can it be anyone else?—— Then, it must be Bob. I saw him go into the toilet just now.二、may 表示“可以，可能”，否定形式may not(1) 表示没有把握的推测，“可能，也许”。

e.g. He may have a lot of work to do. = Maybe he has a lot of work to do.You may be right. = Maybe you are right.(2) 表示请求“我可以……吗？”表示许可“你可以……” e.g. You may /can go now.——May I use your pen?——Yes, you may. / Yes, please. / Go ahead.——No, you can’t. / mustn’t.三、must 表示“必须，肯定，一定”，否定形式mustn’t = must not(1) 表示必须，意思同have toe.g. ——Must I do it now?——Yes, you must.——No, you don’t have to. / No, you needn’t. (注意：否定回答不用mustn’t)Children mustn’t play on the road because it’s too dangerous. (mustn’t只表“禁止”)He doe sn’t have to go away from here.=He needn’t leave here.区别：①must表达主观意愿的“必须”，have to表达客观上或按道理说“不得不”。

e.g. I must study hard.It’s too late. I have to go now.②must 没有人称和时态的变化，而have to有。

e.g. He had to walk back home because he lost all his money.Mom will be away for a week, so we will have to do the cooking by ourselves.(2) 表示有把握的肯定句中的推测，“肯定，一定”，见“一、（5）”四、need 表示“需要”，否定形式needn’t = need not(1)作情态动词，仅用于否定句和疑问句。

e.g. He needn’t go home early yesterday. = He didn’t need/have to go home early yesterday.Need I call him right now? ——Yes, you must.(注意：肯定回答不用need)——No, you needn’t. /No, you don’t have to.(2)作实义动词，need sth./sb.need to do sth. 否定形式don’t need to = don’t have to 表示“不必”e.g. I need some help.He needed to go home early yesterday.Do I need to call him right now? ——Yes, you do. / ——No, you don’t.(3) need 作名词be in (great) need of sth = need sth (badly) “非常需要某物”meet the need “满足需要（需求）”there is/was no need (for sb) to do sth “某人没必要做某事”五、should 表示“应该”，否定形式shouldn’t = should note.g. We should try our best to help the poor little girl.You shouldn’t be lazy.六、had better do表示“最好是做……”，否定形式had better not doe.g. You’d better not drink so much coffee.区别：It’s better for you to do more exercise and not to have so much junk food.七、would 表示意愿常见句型：①表请求Would you please do…? ——OK…. / Sorry, ….②Would you like sth? ——Yes, please. / No, thanks.Would you like to do sth? ——I’d love to.——I’d love to, but….(注意：以上句型中，some不变any)情态动词精选练习1. _____ I go out to play now，Mum? No，you______ ．A．May，shouldn’t B．Can，needn’tC．Must，can’t D．May．mustn’t2. Help me with this case．_______ you?A．don’t B．will C．do D．shall3. They started early that morning in order that they______ there before noon．A．might get B．may get C．would get D．got4. A teacher do every exercise，but a pupil________．A．needn’t，must B．may not，must C．needn’t, needn’t D．can’t, must 5. If you _____ do as I tell you，you______ go to the party．A．can，shan’t B．will, won’t C．won’t，shall D．won’t, shan’t A．will B．would C．do D．can7. Don’t believe him．His story ______ be true．A．mustn’t B．needn’t C．shouldn’t D．may not8. ---She must have gone back to the valley．---No, she ____ . The entrance to it was nowhere to be found．A．mustn’t B．needn't C．couldn’t D．hadn’t9. You need not do it at once,________?A．needn’t you B．mustn’t youC．don’t you D．need you10. He must be in the classroom．______ he?A．mustn’t B．can’t C．isn’t D．Can11. Let’s go to the library．shall we? ________．A．No，I can’t B．Yes．I will C．Yes，thank you D．No，We’d better not 12. You ought to have called him yesterday．Yes, I know I_______．A．ought to B．ought to haveC．ought to have done D．ought to have called13. ---Why did you keep it a secret from me?---I ____ about it．A．should be told B．ought to have been toldC．should have told D．ought to be told14. The work _______ be finished in such a short time．A．wasn’t able to B．couldn’t C．ought D．could15. He looks very tired．He ____ to bed too late last night．A．must go B．must have gone C．could go D．didn’t go16. The door ______ lock．A．can’t B．may not C．won’t D．mustn’t17. As a soldier，you ______ do as the head tells you．A．will B．shall C．may D．ought18. How _____ you be so careless?A．can B．will C．could D．may19. I talked for a long time，and in the end I____ make her believe me．A．could B．can C．must D．was able to20. Did you scold him for carelessness ? Yes，but _____ it．A．I’d rather not do B．I’d rather not have doneC．I shouldn’t do D．I’d better n ot do21. He needn’t come to attend the meeting．_______ ?A．didn’t he B．doesn’t he C．need he D．must he22. Fish _______ die without water．A．will B．should C．shall D．must23. We’d better hurry．Our teacher _________ us．A．wait for B．must wait forC．must be waiting for D．has waited for24. I saw him leave the room an hour ago．He ______ at this time．A．mustn’t be working B．can’t be workingC．can’t work D．may not being working25. ______ basketball every day?A．Did you used to playing B．Did you use to playC．Use you to play D．Used you play26. Why______ you keep on troubling me with such questions while I am busy ?A．could B．can C．must D．will27. ---You were driving at 100km an hour, sir．---But officer，I____ ，my car can’t go more than 90.A．may not have been B．couldn’t have beenC．would have been D．needn’t have been28. You ______ call him if you want to，but you______ ，for he’ll surely come here soon．A．can，needn’t B．may, mustn’tC．have to，needn’t D．can, doesn’t need29. At last he _____ finish the work ahead of time．A．could B．was able toC．could have done D．would have been able to30. There must be some enemy soldiers in the forest._______ any behind the church?A．Must there be B．Should there be C．May there be D．Can there be 31. The shy girl____ dance before so many strangers，______she?A．daren’t，does B．daren’t，dare C．doesn’t，dare D．dare not．Dares 32. “When ___ he leave the hospital?” I asked the doctor．A．will B．shall C．can D．may33. ---They haven’t finished the work up to now．---Well，they______.A．should have B．should C．ought to D．ought have34. The money was soon spent，so she ______ go hungry．A．must B．had to C．might D．Should35. Jack studied hard and _______ pass the examination．A．could able to B．would C．was able to D．ought36. You don’t look well，you _______ have a fever．A．might B．can C．shall D．should37. You are running a fever，you _____ to see the doctor．A．need go B．must have gone C．should go D．can go38. I ______ take the job．No one ____ stop me．A．will，can B．can，must C．must，can D．will, must39. There used to be a high tower here，______ ?A．was there B．wasn’t there C．used there D．usedn’t there 40. Whenever the teacher was not there, the children _______ make a lot of noise．A．will B．would C．were to D．were going to41. He must be shy, _______ he?A. A．must B．mustn’t C．is D．isn’t42. I must do it, ________ I?A．do B．don’t C．must D．mustn’t43. You did not go to the party yesterday, or I ___ you.A．would see B．could meet C．might have seen D．might see 44. ---How do you like the food here?---Oh，excellent! We ______ a better hotel．A．can’t find B．won’t findC．mustn’t have found D．couldn’t have found45. ---We were waiting for you this time yesterday．---Sorry，I ______ you to tell you that I couldn’t come.A．must have called B．would have been callingC．could have been calling D．should have called46. ---Would you mind returning the book tomorrow?---______．A．Ok，I will B．Sure, I wouldn’tC．Yes，I wouldn’t D．Why, I wouldn’t47. See who’s t here! _____ it be Mary?A．May B．Must C．Can D．Will48. My little son ______ out a1one at night．A．dares not go B．dares not to goC．dare not to go D．doesn’t dare to go49. You ______ miss seeing so good a film，i t is one of the best films I’ve ever seen．A．had better not to B．have better not toC．had better to not D．had better not50. It is strange that she _______ so．A. think B．thinks C．will think D．thought51. _______ you rather sit at the back?A．Won’t B．Wouldn’t C．Don’t D．Will52. ---Where______?---She ______ to school, for it is Sunday today．A．can she go，can’t go B. may be go，may not goC．can she have gone, can’t hav e gone D．can she go，can’t have gone 53. Since she is angry, we _____．A．had better to leave her alone B．should leave her alone C．might as well leave her alone D．must leave her alone54. ---Do you think he will do me a favour?---It’s very unlikely，but he ____ be prepared to help you．A．must B．will C．can D．Might55. Will you sing a song at the party? No, I_________．A．wouldn’t B．won’t C．shouldn’t D．shall not56. My brother used to get up early in the morning，but my sister seldom ______.A. used toB. didC. usedD. both A and B57. ---Will it be raining this afternoon?---No，I’m afraid it_____．A．may not B．won’t C．mustn’t D．shouldn’t58. You _____ in such a hurry，I’ll have the car waiting for you．A．don’t need being B．don’t have beenC．need not to be D．needn’t be59. I have kept the book for 3 weeks．I _______ them to the library last week．A．ought return B．ought to returnC．ought have returned D．ought to have returned60. ---______ I get you some food?---No．thanks．A. A．MightB. ShallC. WillD. Ought中考考点情态动词练习1. -Mum，may I watch TV now？-Sure，but you ________ help me with my English.A. canB. mayC. mustD. could2. -________ I download the article again？-No，you needn't.A. ShallB. WillC. MustD. Can3. -Can you go skating with us this afternoon？-Sorry，I can't. I ________ take care of my little sister at home.A. canB. mayC. wouldD. have to4. -Must I hand in my exercise book today？-No，you ________.A. can'tB. needn'tC. mustn'tD. won't5. -May I have a word with you？-No，you ________. I'm busy today.A. needn'tB. wouldn'tC. don't have toD. can't6. -________I have your English name，please？-Yes，Helen. H-E-L-E-N.A. MustB. MayC. WillD. Need7. -Who is the boy over there？Is it John？-No，it ________ be him. John is much taller.A. mustn'tB. may notC. can'tD. needn't8. -Can you play Frisbee，Jay？-Yes，I ________. It's easy.A. mustB. canC. needD. may9.-You must come back every month. -Yes，I ________.A. willB. mustC. shouldD. can10. She ________ know the answer，but I'm not sure.A. maybeB. may beC. mayD. must11. - Must we clean the room right now？- No，you. You clean it after lunch.A. needn't；mayB. needn't;mustC. Mustn't；canD. mustn't；may12. John________ come to see us tonight，but he isn't very sure yet.A. mayB. canC. has toD. must13. Children ________ play with fire.A. mustn'tB. can'tC. shouldn'tD. needn't14. -________ I come in，Mr Green？-Yes,come in，please.A. MustB. NeedC. WillD. May15. -Must I finish the work today？-No，you ________. You ________ finish it tomorrow.A. mustn't；mayB. can't；canC. needn't；mayD. needn't；must1-5 DBAAD 6-10 ADCDC 11-15 DBBBB 16-20 CBADB 21-25 CACBB 26-30 CBABD 31-35 BBABC 36-40 ACADB 41-45 DDCDD46-50 DCDDA 51-65BCCDB 56-60DADDB1. C.这组对话的意思是："妈妈，我现在可以看电视吗？""当然，但你必须帮我学英语。