M4U2情态动词课件

1、 Whats the definition of modal verbs?l情态动词是一种本身有一定的词义情态动词是一种本身有一定的词义,表表示说话人的情绪示说话人的情绪,态度或语气的动词态度或语气的动词,但但不能单独作谓语不能单独作谓语, 只能和其他动词原形只能和其他动词原形构成谓语。构成谓语。 一一.情态动词的语法特征情态动词的语法特征1）情态动词情态动词不能单独做谓语，除不能单独做谓语，除ought和和have外，后面只能接不带外，后面只能接不带to的的不定式。不定式。2）情态动词没有人称，数的变化，但有些情态动词没有人称，数的变化，但有些情态动词，如情态动词，如can、will也有一般

2、式和过去也有一般式和过去式的变化。式的变化。3）情态动词的情态动词的“时态时态”形式并不是时间区形式并不是时间区别的主要标志，不少情况下，情态动词的现别的主要标志，不少情况下，情态动词的现在式形式和过去式形式都可用来表示现在时在式形式和过去式形式都可用来表示现在时间、过去时间和将来时间。间、过去时间和将来时间。1. Ability （能力）（能力）2. Obligation （义务）（义务）3. Certainty （可能性）（可能性）4. Permission （允许）（允许）二情态动词的语法功能二情态动词的语法功能5. Make requests（提出（提出请求请求）6. Make sug

3、gestions（提出（提出建议建议）7. Make offers（提供（提供帮助帮助）8. Give advice（提出（提出意见意见）情态动词1. can could be able to4. shall 2. may might三常见情态动词的基本用法5. must have to 3. will would7. need dare6. ought to should8. 情态动词+have done情态动词1. can could be able to3. shall 2. may mightThe usage of some common modal verbs4. must hav

4、e to 5. 情态动词+have donel1.canl1)表能力表能力can表能力时意味着凭体力或脑力或技术等可以无甚阻力地去做某事。lI can climb this pole. He is only four , but he can read. lFire cant destroy gold. can 和和could：l2)表推测、可能性表推测、可能性(用于否定与疑问结构中用于否定与疑问结构中)lCan the news be true? It cant be true. lWhat can he possibly mean? 他可能是什么意思?l3)表示表示请求或允许请求或允许(和

5、和may意思相近意思相近)常见于常见于口语。口语。lCan (May) I come in ? 我能进来吗?lCan I smoke here ? 我可以在这里抽烟吗?2)could的主要用法是：的主要用法是：A.could是是can的过去式的过去式,表示与过去表示与过去有关的能力和推测有关的能力和推测:eg.Weallknewthattheyoungmancouldntbeadoctor.B.could可以代替可以代替can表示请求、表示请求、允许允许。可表示委婉客气的提出问题或陈述看法Couldyoulendmeyourdictionary?CouldIuseyourbike?Yes, y

6、ou can.Im afraid I couldnt give you an answer today.can/be able to区别区别:can表示表示或或，而，而be able to更加强调更加强调或者或者，能做到的事情。能做到的事情。I cant swim, but I am sure I will be able toswim through more practicing.表示特定的某一过去能力或表示成功地做表示特定的某一过去能力或表示成功地做了某事时，只能用了某事时，只能用was/were able to， 不不能用能用could。 He_fleeEuropebeforethew

7、arbrokeout.Note：wasableto1.A big fire broke out in ABC hotel yesterday. Luckily, everyone _ run out of the building.was able to2. She _ speak both English and French.canI cant thank you too much.can never/canttoo表示表示“无无论怎样论怎样也不过分也不过分”，“越越越越好好” 。你过马路的时候再小心也不为过。你过马路的时候再小心也不为过。 You cant be too careful

8、while crossing the road. She couldnt but agree to my idea.I cant thank you enough.The film couldnt be any worse.Can或或could 的否定形式构成习惯短语的否定形式构成习惯短语Cant.too.Cant .enough.无论怎样无论怎样也不过分也不过分Cant (help) but do不得不做，只好做不得不做，只好做Cant help doing 情不自禁情不自禁Cant help it 没有办法没有办法Cant .+比较级比较级 再再不过了（表示最高级）不过了（表示最高级）Ma

9、yIwatchTVaftersupper?Yes,_./No,_.MightIuseyourtelephone?MayIgohomenow?Itmaybetrue.Shemaycometomorrow.Hemighthavesomefever.Mayyousucceed!Mayyouhavemanymoredaysashappyasthisone!youmayYoumustnt允许允许,许可许可禁止禁止,阻止阻止Might比比May的语气更委婉的语气更委婉表示可能性的推测表示可能性的推测,译为译为“大概大概,可能可能”用用might时显得更加不肯定时显得更加不肯定用于祈使句表示祝愿用于祈使句表

10、示祝愿.May和和Mightl A computer _ think for itself; it must be told what to do.l A. cant B. couldnt l C. may not D. might notAmay_can_表主观表主观“可能可能”表客观表客观“可能可能”cannot_maynot_不可能不可能可能不可能不may和和canThey_ be doing the experiment in the lab.Why？Because the lights are still burning.A.could B.can C.must D.would wi

11、ll和和would：will当作情态动词时有以下用法当作情态动词时有以下用法:If you give him time, Tom will talk and talk for hours.Every Saturday evening they will play chess together表经常性，习惯性表经常性，习惯性“老是、总是、终归老是、总是、终归是是”lThe door wont open.lIll do my best to help you.lWill you please give me a message when you see him?l-Write to me when

12、 you get home.l-I will.表示功能，译作表示功能，译作“能能”或或“行行”意愿意愿2人称，询问对方意愿或向对人称，询问对方意愿或向对方提出请求方提出请求回答祈使句回答祈使句Would当作情态动词时有以下用法：当作情态动词时有以下用法：Wouldyouhelpus,please?WhenIhadsometrouble,hewouldencourageme.Wealltriedtostophimsmokinginbedbuthewouldntlisten.过去的习惯过去的习惯意愿意愿“要；愿要；愿”用于用于2人称，表示有礼貌的请求或邀请人称，表示有礼貌的请求或邀请Would 与

13、与 Used to do 区别区别 “过去常常过去常常” Would -过去习惯的动作动作（现在有可能还有此习惯）Used to do -过去习惯的动作动作及状态（现在已经没有此习惯） The old man _have a smoke under a big tree every afternoon after he finished his farm work. would可表示经常性、习惯性、倾向性。可表示经常性、习惯性、倾向性。翻译为翻译为“经常、惯于、总是经常、惯于、总是”。shall和和should：1.shall用于征求对方的意见，表用于征求对方的意见，表“决心决心”Shallw

14、egobytrain,Mom?妈妈，我们乘火车去好吗？妈妈，我们乘火车去好吗？（用于征求对方的意见）（用于征求对方的意见）Ishallgoatonce.我必须立即去。我必须立即去。（表（表“决心决心”）l1)用于第一、用于第一、 三人称征求对方的意见，三人称征求对方的意见，lWhat shall he wear on the journey? lShall we dance? l2)shall 用于第二、三人称时表允诺，警告，用于第二、三人称时表允诺，警告，命令，威胁。命令，威胁。“必须，应该可以必须，应该可以”lIf he passes the examination, he shall h

15、ave a holiday.lYou shall have it back tomorrow.l3）用于第二、三人称用于法律法规条例等）用于第二、三人称用于法律法规条例等文件中的要求。文件中的要求。“应该、必须应该、必须”lIts required in our regulation that students shall go to school on time.lPersons under 18 shant be employed in night work.l2.should表示义务、建议、劝告等，意为表示义务、建议、劝告等，意为“应该应该”。(oughtto)lStudentsshou

16、ldrespectteachers.lTheboysshouldntbeplayingfootball;theyshouldbeatschool.lIts4:30,TheyshouldbeinNewYorkbynow.劝告、建议劝告、建议义务、责任义务、责任常规、常理的推测（正常情况下）按理应该常规、常理的推测（正常情况下）按理应该lHeoughttosucceed,asheissodiligent.lItisstrangethatitshouldbesohottoday.lIdontunderstandwhysheshouldhavemadesuchamistake.lShoulditrai

17、ntomorrow,themeetingwillbepostponed.居然，竟然居然，竟然与疑问词连用，表示意外、纳闷、惊讶等与疑问词连用，表示意外、纳闷、惊讶等“究竟是，到底究竟是，到底”用于条件句中用于条件句中“万一万一”l - Whats the name?l - Khulaifi. _ I spell that for you?A. Shall B. Would C. Can D. MightDrill(小练小练)（10江苏）江苏） I havent got the reference book yet, but Ill have a test on the subject next

18、 month. Dont worry. You_ have it by Friday. A. could B. shall C. must D.may 解析：解析：shall在第二人称中表示在第二人称中表示允诺允诺，还，还可以表示强制，命令，威胁，警告。还可以表示强制，命令，威胁，警告。还有在法律条文中的要求或规定。有在法律条文中的要求或规定。答案：答案：BYoushallbepunishedforwhatyouvedone.你一定会因为你的所作所受到惩罚。你一定会因为你的所作所受到惩罚。must和和haveto1.must用于一般问句中用于一般问句中,肯定回答用肯定回答用must否定式用否定

19、式用neednt或或donthaveto，做做“不必不必”,mustnt表示表示“禁止，不允禁止，不允许许” MustIfinishalltheworkatatime?Yes,youmust.No,youneednt.IdontlikethisTVset.Wemustbuyanewone.Therewasnomorebus.Theyhadtowalkhome.2.表示表示“必须必须”这个意思时，这个意思时，must和和haveto稍有区别。稍有区别。must着重说明主观着重说明主观看法，看法，haveto强调客观需要。另外，强调客观需要。另外，haveto能用于更多时态。能用于更多时态。 Yo

20、umustbethenewteacher.Hemustbejoking.Thereisnobodyhere.Theymusthaveallgonehome.3.must表示对某人某事的猜测，表示对某人某事的猜测，作作“准准是是”，“一定一定”，一般用于肯定句中。对，一般用于肯定句中。对过去发生的事情作肯定判断用过去发生的事情作肯定判断用musthavedoneHow old are you, madam?If you must know, Im twice my sons age.4.must表示表示“偏要，硬要偏要，硬要”，指做令人，指做令人不快的事情不快的事情need 与与 dare 实义

21、动词实义动词情态动词情态动词.可兼做行为动词的情态动词：need 、 dare情态动词情态动词(+动词原形动词原形)行为动词行为动词 .needdare1.无人称和数的变化;2.尤其用于：*否定句及疑问句中;*在if/whether之后;*或与hardly, never, no one, nobody连用; 3.常以neednt 和darent 的形式出现;4.dare有其过去时dared. 多用于肯定句; need to do dare to doneed to be done need doing 实义动词实义动词 vs 情态动词情态动词肯定句肯定句 实实情情e.g. She needs

22、to stay at home today.e.g. He dares to jump from the high wall.e.g. She need stay at home today.e.g. He dare jump from the high wall.疑问句疑问句 e.g. Does she need to stay at home today?e.g. Does he dare to jump from the high wall?e.g. Need she stay at home today?e.g. Dare he jump from the high wall?实实情情

23、否定句否定句Dare 作为实意动词的时候，作为实意动词的时候，否定句否定句中的中的 to 可以省略可以省略e.g.He doesnt dare (to) jump from the high wall.实实e.g. She doesnt need to stay at home today.e.g. He doesnt dare to jump from the high wall情情e.g. She neednt stay at home today.e.g. He dare not jump from the high wall. must have done must have done

24、 过去一定做过某事cant have donecant have done 过去不可能做过某事should ( ought to ) have doneshould ( ought to ) have done 过去本该做某事却没做shouldnt ( ought not to ) have done shouldnt ( ought not to ) have done 过去本不该做某事却做了. 情态动词+have done表示对已经发生事情推测、责怪、后悔、遗憾等。 neednneednt have donet have done 过去没有必要做某事而实际上却做了 could have d

25、one could have done 过去本可以做某事却没做might have donemight have done 过去可能已经做了某事5. 情态动词+have done表示对已经发生事情推测、责怪、后悔、遗憾等。l1. It must have rained last night, for the streets are wet.l2. He looks very happy. He might not have known the result.l3. He could not have done such a thing.l4. She didnt come to school

26、yesterday. Can she have been ill?l5. They left here early and should have arrived by now.情态动词表推测情态动词表推测 对过去情况的推测对过去情况的推测l6. You might have written the letter without my reminding you of it.l7. The doctor could have avoided the accidentl8. You should have finished the task yesterday.l9.I was really a

27、nxious about you,you shouldnt have left home without a word.l10.He ought not to have told me your secret,but he meant no harm.过去本可能（不用过去本可能（不用may)过去本能够过去本能够却没有却没有过去本应该过去本应该却没有却没有过去本不该过去本不该过去本不该过去本不该1.Theweatherturnedouttobefineyesterday.I_thetroubletocarrymyumbrellawithme.A.shouldhavetakenB.couldhav

28、etakenC.neednthavetakenD.mustnthavetaken2.-IlltellMaryabouthernewjobtomorrow.-You_herlastweek.A.oughttotellB.wouldhavetoldC.musttellD.shouldhavetoldCDPracticePractice3.She_haveleftschool,forherbikeisstillhere.A.cantB.wouldntC.shouldntD.neednt4.-Icantfindmypurseanywhere.-You_havelostitwhileshopping.A

29、.mayB.canC.shouldD.would5.-IstayedatahotelwhileinNewYork.-Oh,didyou?You_withBarbara.A.couldhavestayedB.couldstayC.wouldstayD.musthavestayedAAAl表推测的情态动词句子的反意疑问句表推测的情态动词句子的反意疑问句He must/may be in the room, isnt he?He cant be in the room, is he?He must have finished the work, hasnt he?He may have done t

30、he work last night, didnt he? He must have been caught in the heavy rain last night,_wasnt he.l （10四川）四川）l 1. _ I take the book out? Im afraid not. A. Will B. May C. Must D. Need考点：考查情态动词。解析：表请求可用情态动词can, may, could, might ,表允许用can, may.句意为：“我可以将这本书带出去吗？”“恐怕不行”。故应选表请求的情态动词may。正确答案为B。答案：B(10陕西）陕西）l 2

31、. -May I take this book out of the reading room? -No, you . You read it in here. l A. mightnt B. wont l C. neednt D. mustnt解析：考查情态动词。英语中用could，might表示询问或征求意见的问句中，肯定性应答要用can或may来代替could或might，而may或might征求意见的问句否定应答时要用mustnt，表示禁止.故本题选D。答案：Dl （10湖南）l3. You_buy a gift, but you can if you want to.lA. must

32、 B. mustnt lC. have to D. dont have to 考点：情态动词解析：dont have to 意为“没有必要”，符合语境，句意为：“你没有必要买礼物，但如果你想买的话，你也可以买。”答案：Dl （10浙江）浙江）l 4. “You _ have a wrong number,” she said. “Theres no one of that name here.”l A. need B. can l C. must D. would 考点：情态动词解析：肯定猜测，用must答案：Cl （10全国全国）l 5.Im afraid Mr. Harding _see you now. Hes busy.l A. cant B. mustnt C. shouldnt D .neednt解析：情态动词考查。结合语境，根据情态动词用于疑问或否定推测时，要用cant。答案：Al 6. I cant thank you too much for your kindness, because without your help I_have won the first prize in t