初中教育高中情态动词.pptx

高中英语语法之情态动词高中英语语法之情态动词Modal Verb语法特征语法特征（features in Grammar）1 情态动词没有人称，数的变化。情态动词没有人称，数的变化。2 情态动词没有非谓语形式。情态动词没有非谓语形式。3 情态动词后面接不带情态动词后面接不带to的不定式，的不定式，ought和和have除外。除外。Modal Verbscan/may 1.表示表示能力能力的情态动词用的情态动词用can/could(过去式过去式)。e.g.A computer _ think for itself,it must be told what to do.A.cant B.couldnt C.may not D.might not2.表示表示许可许可时用时用may/might,can/could 都可以，但在问句中都可以，但在问句中用用could或或might,表示委婉客气，其回答一定要用表示委婉客气，其回答一定要用can或或may，以使回答口气明确。，以使回答口气明确。May I/we.？表示许可疑问句的肯定回？表示许可疑问句的肯定回答为答为 Yes，please.或或 Certainly；否定回答为；否定回答为 Please dont.或或 No，you mustnt.e.g.-Could I have the television on?-Yes,you can./No,you cant.-May we leave now？-No,you mustnt.You havent finished your homework yet.A典型例题典型例题：-Could I borrow your dictionary?-Yes,of course,you _.A.might B.well C.can D.should -Could I call you by your first name?-Yes,you_.A.will B.could C.may D.might CC3.can/could/may/might 都可以表示都可以表示可能性可能性。can/could 表示潜在的可能性或理论上或逻辑判上存表示潜在的可能性或理论上或逻辑判上存在的可能性；而在的可能性；而 may/might,则表示事实上的可能则表示事实上的可能性性。e.g.According to the weather forecast,it may rain tomorrow.此外此外,can/could 还有还有“有能力有能力”的意思的意思,而而may与与 might 不具有此意不具有此意。e.g.Any man with a little sense can see that he is wrong.典型例题：典型例题：1.-I cant find my purse anywhere.-You _ have lost it while shopping.A.may B.can C.should D.would2.Some people who dont like to talk much are not necessarily shy;they just_ be quiet people.A.must B.may C.should D.wouldAB4.表示祝愿、祝福表示祝愿、祝福的的may,句子用倒装语序。句子用倒装语序。May he live to an old age!愿他长命百岁愿他长命百岁!May God be with you!愿上帝保佑你愿上帝保佑你!can 与与 be able to 的区别：的区别：1.can表示能力；可能。表示能力；可能。Be able to 表示经过努力后成功做成某事。表示经过努力后成功做成某事。e.g.He can ride a horse.He was able to flee Europe before the war broke out.=He managed to flee Europe before the war broke out.2.can 只能用于现在式和过去式只能用于现在式和过去式(could)；be able to 可以用于各种时态。可以用于各种时态。e.g.They will be able to tell you the news soon.考点考点1:can 用于推测表示可能性时，通常用于推测表示可能性时，通常用于否定句和疑问句中，而不用于肯定句。用于否定句和疑问句中，而不用于肯定句。而而could既可用于否定句和疑问句，也可用既可用于否定句和疑问句，也可用于肯定句，此时的于肯定句，此时的could并不是并不是can的过去的过去式，只是比式，只是比can的语气更委婉。的语气更委婉。e.g.You _ be right,but I dont think you are.A.can B.could C.must D.shouldBcan 在以下特殊情况下，也可以用于肯定句：在以下特殊情况下，也可以用于肯定句：1表示抽象的可能性，即从理论或逻辑上分析是可能的，但实表示抽象的可能性，即从理论或逻辑上分析是可能的，但实际上未必会发生。际上未必会发生。e.g.Anyone can make mistakes.2 后接后接“be(get,seem,become)+adj.”,表示表示“有时会有时会”、“时常会时常会”等。等。e.g.My father can be very unreasonable.典型例题：典型例题：1.It is usually warm in my hometown in March,but it _ be rather cold sometime.A.must B.can C.should D.would2.Peter _ be really difficult at times even though hes a nice person in general.A.shall B.should C.can D.mustBC考点考点2：提出委婉的请求，注意在回答中不能用提出委婉的请求，注意在回答中不能用could。e.g.-Could I have the television on?-Yes,you can./No,you cant.典型例题典型例题：-Could I borrow your dictionary?-Yes,of courseyou _.A.might B.well C.can D.shouldC考点考点3：构成下列特殊句式的构成下列特殊句式的can。cannot too是一个常考的词组，意为是一个常考的词组，意为“无论怎样无论怎样也不算过分，也不算过分，越越越好越好”，有时也可用，有时也可用can never,impossible等与等与too 连用表示类连用表示类似意思。似意思。e.g.You cant be too careful.A women cannot have too many clothes.Since it is a good thing,we cannot do it too soon.典型例题：典型例题：You _ pay too much attention to your reading skill,as it is so important.A.cannot B.shouldnt C.mustnt D.neednt cant help doing,cannot help but do,cannot but do“禁不住，禁不住，不由得，不得不不由得，不得不”e.g.I cannot help admiring the picture whenever I look at it.每当我看到这幅画时，我都禁不住要鉴赏它。每当我看到这幅画时，我都禁不住要鉴赏它。When a close friend dies,you cannot but feel sad.亲密的朋友去世时，你会不由得感到悲伤。亲密的朋友去世时，你会不由得感到悲伤。A shall/should1.Shall 用于第一、三人称表示征求对方的意见用于第一、三人称表示征求对方的意见 What shall we do this evening?Shall I open the window?2.shall 用于第二、三人称表示允诺、告诫、警告、用于第二、三人称表示允诺、告诫、警告、威胁、命令、规定、必然性等。威胁、命令、规定、必然性等。You shall fail if you dont work harder.(警告警告)He shall have the book when I finish reading.(允诺允诺)He shall be punished.(威胁威胁)The fine shall be given in cash.罚款须以现金缴罚款须以现金缴纳。（规定）纳。（规定）Shall 典型例题：典型例题：“I promise that she _ get a nice present on her birthday.”“Will it be a great surprise to her?”A.should B.must C.would D.shallEach competitor _ wear a number.A.will B.can C.shall D.mayCD（表义务、责任的）应该（表义务、责任的）应该 You should apologize to him.（表预期的）应该会，想必会，一定（表预期的）应该会，想必会，一定 The photos should be ready by 12:00.（表惊讶、遗憾的）竟然、居然（表惊讶、遗憾的）竟然、居然 Im surprised that you should speak in such a way.（与疑问词连用，表意外、惊讶、纳闷等的）究竟是，（与疑问词连用，表意外、惊讶、纳闷等的）究竟是，到底到底 Who should come in but my old friend Betty.我当究竟是谁进来了呢，原来是我的老朋友贝蒂呀。我当究竟是谁进来了呢，原来是我的老朋友贝蒂呀。（用于表示命令、建议、请求等词后面的（用于表示命令、建议、请求等词后面的that从句中，从句中，且且should可以省略）应该，必须可以省略）应该，必须 I suggested that he(should)change his mind.My suggestion was that he(should)change his mind.Should 典型例题：典型例题：According to the air traffic rules,you _ switch off mobile phone before boarding.A.may B.can C.would D.should-I dont care what people think.-Well,you _.A.could B.would C.should D.might DCwill/would请求、建议，请求、建议，would比比will委婉客气委婉客气 Would you pass me the book?表示意志、愿望和决心表示意志、愿望和决心 I will never do that again.They asked us if we would do that again.可表示可表示过去过去反复发生的动作或某种倾向反复发生的动作或某种倾向 During the vacation he would visit me every week.The wound would not heal.表示估计或猜想表示估计或猜想 It would be about ten when he left home.What would she be doing there?典型例题：典型例题：John promised his doctor he _ not smoked,and he has not smoked ever since.A.might B.should C.could D.wouldDdare/need1.need和和dare既可作实义动词，又可作情态既可作实义动词，又可作情态动词。作为情态动词，两者都只能用于否定动词。作为情态动词，两者都只能用于否定句、疑问句和条件句。句、疑问句和条件句。I need finish this project today.If he dare come,I will kick him out.I dont know whether he dare say.2.need 作为实义动词，后面加不定式；作为实义动词，后面加不定式；dare作为实义动词时，后面的作为实义动词时，后面的to时常可以省略。时常可以省略。He needs to go home before 7pm.He doesnt dare(to)answer the question.Does she dare(to)enter the dark room?3.注意情态动词注意情态动词need提问时的回答：提问时的回答：-Need you go yet?-Yes,I must./No,I neednt.4.need 的被动含义：的被动含义：need/want/require/worth+doing也可以也可以表示被动。表示被动。need doing=need to be done This house need repairing=(need to be repaired).must/have tomust 和和 have to 都可以表示都可以表示“必须必须”，但有几点区别：但有几点区别：(1)must 强调主观需要，而强调主观需要，而 have to 强调客观要求。强调客观要求。He said that they must work hard.(主观主观)My brother was ill,so I had to call the doctor in the middle of night.（客观）（客观）It is raining hard outside,but I have to leave now.(2)have to 可用于多种时态，而可用于多种时态，而 must 一般用于现在时，一般用于现在时，其过去时与将来时分别由其过去时与将来时分别由 had to 与与 shall/will have to 代代替替。(3)在回答在回答 must 引起的问题时，如果是否定的答复，不能引起的问题时，如果是否定的答复，不能用用 mustnt，而要用，而要用 neednt 或或 dont have to，因为，因为 mustnt 表示表示“禁止禁止”的意思的意思。例如：例如：“-Must we do it now？”“No,you neednt.”(4)must 用在肯定句中表示较有把握的推用在肯定句中表示较有把握的推测，意为测，意为“一定一定”，否定推测用，否定推测用cant.If Tom didnt leave here until five oclock,he cant be home yet.(5)must表示对现在的状态或现在正在发生表示对现在的状态或现在正在发生的事情的推测，的事情的推测，must 后面接系动词后面接系动词be或行或行为动词的进行式。为动词的进行式。You have worked hard all day.You must be tired.He must be working in his office.典型例题：典型例题：One of the few things you _ say about English people with certainty is that they talk a lot about weather.A.need B.must C.should D.can-Hi,Tom.Any idea where Jane is?-She _ in the classroom.I saw her there just now.A.shall be B.should have been C.must be D.might have been BC情态动词动词完成式情态动词动词完成式情态动词动词完成式即情态动词动词完成式即“情态动词情态动词havedone”，表示对过去的行为或动作进行推测表示对过去的行为或动作进行推测、评论或判断评论或判断。(1)must have donemust have done 表示对过去某事的肯定猜测表示对过去某事的肯定猜测。其否定其否定或疑问形式都用或疑问形式都用 can(could)来表示来表示。例如：例如：Since the road is wet,it must have rained last night.He cant have missed the way.I drew him a map.The dictionary has disappeared.Who could have taken it?(2)may/might have donemay/might have done 表示推测过去某事表示推测过去某事“也许也许”发生了发生了，may 比比 might 表示的可能性表示的可能性在说话人看来稍大些在说话人看来稍大些。例如：例如：I cant find my keys.I may/might have left them at the school yesterday.(3)could have done 在肯定句型中在肯定句型中，往往表示委婉的批评往往表示委婉的批评。本可本可以做什么而没做；有时也用作猜测以做什么而没做；有时也用作猜测。You could have told us earlier.Tom could have taken the dictionary.(4)ought to/should have done ought not to/shouldnt have doneought to/should have done和和ought not to/shouldnt have done用于对已发生的情况表示用于对已发生的情况表示“责备责备”、“不不满满”，分别表示分别表示“本应该本应该”和和“本不应该本不应该”。例如：例如：1)With all the work finished，I should have gone to the party last night.2)You ought not to have made fun of him.He is not the one you laugh at but learn from.(5)neednt have doneneednt have done 表示过去做了某事表示过去做了某事，但没有做的但没有做的必要必要，意为意为“本没必要本没必要”。例如：例如：Yon neednt have waken me up;I dont have to go to work today.注：注：表示推测过去某动作发生的可能性时，表示推测过去某动作发生的可能性时，就表示的可能性程度而言，就表示的可能性程度而言，must 最大，最大，could 其次，其次，may 更次之，更次之，might 最小。例最小。例如：如：I wonder how Tom knew about your past.He must/could/may/might have heard of it from Mary.典型例题：典型例题：-Im sorry.I _ at you the other day.-Forget it.I was a bit of control myself.A.shouldnt shout B.shouldnt have shouted C.mustnt shout D.mustnt have shouted Thank you for all your hard work last week.I dont think we _ it without you.A.can manage B.could have manage C.could manage D.can have manage What a pity.Considering his ability and experience,he _ better.A.need have done B.must have done C.can have done D.might have doneBBD情态动词动词进行式情态动词动词进行式情态动词行为动词进行式情态动词行为动词进行式(即情态动词即情态动词bedoing)，表示推测或评论某动作现在是否表示推测或评论某动作现在是否正在进行正在进行。例如：例如：(1)He must be playing basketball in the room.(2)She may be staying at home.其他情态动词其他情态动词 used to 表示过去的习惯动作或状态表示过去的习惯动作或状态(现在已不现在已不复如此复如此)Did you use to go there to see your brother?/Used you to go there to see your brother?Yes,I did(used to)./No,I didnt(usednt).had better表示表示“最好最好(做做)”We had better go now.其否定式为其否定式为had better not would rather do 表示宁愿表示宁愿;would ratherthan表示宁愿表示宁愿而不愿。而不愿。If I have a choice,I would rather continue my study at this school.I would rather stay here than go home