高中情态动词课件 31页

高中英语语法之情态动词ModalVerb\n语法特征（featuresinGrammar）1情态动词没有人称，数的变化。2情态动词没有非谓语形式。3情态动词后面接不带to的不定式，ought和have除外。\nModalVerbscan/may1.表示能力的情态动词用can/could(过去式)。e.g.Acomputer_____thinkforitself,itmustbetoldwhattodo.A.can’tB.couldn’tC.maynotD.mightnot2.表示许可时用may/might,can/could都可以，但在问句中用could或might,表示委婉客气，其回答一定要用can或may，以使回答口气明确。MayI/we...？表示许可疑问句的肯定回答为Yes，please.或Certainly；否定回答为Pleasedon't.或No，youmustn't.e.g.①-CouldIhavethetelevisionon?-Yes,youcan./No,youcan’t.②-Mayweleavenow？-No,youmustn't.Youhaven'tfinishedyourhomeworkyet.A\n典型例题：①-CouldIborrowyourdictionary?-Yes,ofcourse,you___.A.mightB.wellC.canD.should②-CouldIcallyoubyyourfirstname?-Yes,you____.A.willB.couldC.mayD.mightCC\n3.can/could/may/might都可以表示可能性。can/could表示潜在的可能性或理论上或逻辑判上存在的可能性；而may/might,则表示事实上的可能性。e.g.Accordingtotheweatherforecast,itmayraintomorrow.此外,can/could还有“有能力”的意思,而may与might不具有此意。e.g.Anymanwithalittlesensecanseethatheiswrong.\n典型例题：1.-Ican’tfindmypurseanywhere.-You__havelostitwhileshopping.A.mayB.canC.shouldD.would2.Somepeoplewhodon’tliketotalkmucharenotnecessarilyshy;theyjust____bequietpeople.A.mustB.mayC.shouldD.wouldAB\n4.表示祝愿、祝福的may,句子用倒装语序。Mayhelivetoanoldage!愿他长命百岁!MayGodbewithyou!愿上帝保佑你!\ncan与beableto的区别：1.can表示能力；可能。Beableto表示经过努力后成功做成某事。e.g.Hecanrideahorse.HewasabletofleeEuropebeforethewarbrokeout.=HemanagedtofleeEuropebeforethewarbrokeout.2.can只能用于现在式和过去式(could)；beableto可以用于各种时态。e.g.Theywillbeabletotellyouthenewssoon.\n考点1:can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。而could既可用于否定句和疑问句，也可用于肯定句，此时的could并不是can的过去式，只是比can的语气更委婉。e.g.You___beright,butIdon’tthinkyouare.A.canB.couldC.mustD.shouldB\ncan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，但实际上未必会发生。e.g.Anyonecanmakemistakes.2后接“be(get,seem,become)+adj.”,表示“有时会”、“时常会”等。e.g.Myfathercanbeveryunreasonable.典型例题：1.ItisusuallywarminmyhometowninMarch,butit____berathercoldsometime.A.mustB.canC.shouldD.would2.Peter___bereallydifficultattimeseventhoughhe’sanicepersoningeneral.A.shallB.shouldC.canD.mustBC——————————\n考点2：提出委婉的请求，注意在回答中不能用could。e.g.-CouldIhavethetelevisionon?-Yes,youcan./No,youcan’t.典型例题：--CouldIborrowyourdictionary?--Yes,ofcourse,you___.A.mightB.wellC.canD.shouldC\n考点3：构成下列特殊句式的can。①cannot…too…是一个常考的词组，意为“无论怎样…也不算过分，越…越好”，有时也可用cannever,impossible等与too连用表示类似意思。e.g.Youcan’tbetoocareful.Awomencannothavetoomanyclothes.Sinceitisagoodthing,wecannotdoittoosoon.典型例题：You_____paytoomuchattentiontoyourreadingskill,asitissoimportant.A.cannotB.shouldn’tC.mustn’tD.needn’t②can’thelpdoing…,cannothelpbutdo…,cannotbutdo…“禁不住，不由得，不得不”e.g.IcannothelpadmiringthepicturewheneverIlookatit.每当我看到这幅画时，我都禁不住要鉴赏它。Whenaclosefrienddies,youcannotbutfeelsad.亲密的朋友去世时，你会不由得感到悲伤。A\nshall/should1.Shall用于第一、三人称表示征求对方的意见Whatshallwedothisevening?ShallIopenthewindow?2.shall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。Youshallfailifyoudon’tworkharder.(警告)HeshallhavethebookwhenIfinishreading.(允诺)Heshallbepunished.(威胁)Thefineshallbegivenincash.罚款须以现金缴纳。（规定）Shall\n典型例题：“Ipromisethatshe___getanicepresentonherbirthday.”“Willitbeagreatsurprisetoher?”A.shouldB.mustC.wouldD.shallEachcompetitor____wearanumber.A.willB.canC.shallD.mayCD\n①（表义务、责任的）应该Youshouldapologizetohim.②（表预期的）应该会，想必会，一定Thephotosshouldbereadyby12:00.③（表惊讶、遗憾的）竟然、居然I’msurprisedthatyoushouldspeakinsuchaway.④（与疑问词连用，表意外、惊讶、纳闷等的）究竟是，到底WhoshouldcomeinbutmyoldfriendBetty.我当究竟是谁进来了呢，原来是我的老朋友贝蒂呀。⑤（用于表示命令、建议、请求等词后面的that从句中，且should可以省略）应该，必须Isuggestedthathe(should)changehismind.Mysuggestionwasthathe(should)changehismind.Should\n典型例题：①Accordingtotheairtrafficrules,you___switchoffmobilephonebeforeboarding.A.mayB.canC.wouldD.should②-Idon’tcarewhatpeoplethink.-Well,you___.A.couldB.wouldC.shouldD.mightDC\nwill/would①请求、建议，would比will委婉客气Wouldyoupassmethebook?②表示意志、愿望和决心Iwillneverdothatagain.Theyaskedusifwewoulddothatagain.③可表示过去反复发生的动作或某种倾向Duringthevacationhewouldvisitmeeveryweek.Thewoundwouldnotheal.④表示估计或猜想Itwouldbeabouttenwhenhelefthome.Whatwouldshebedoingthere?\n典型例题：Johnpromisedhisdoctorhe___notsmoked,andhehasnotsmokedeversince.A.mightB.shouldC.couldD.wouldD\ndare/need1.need和dare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句、疑问句和条件句。Ineedfinishthisprojecttoday.Ifhedarecome,Iwillkickhimout.Idon’tknowwhetherhedaresay.2.need作为实义动词，后面加不定式；dare作为实义动词时，后面的to时常可以省略。Heneedstogohomebefore7pm.Hedoesn’tdare(to)answerthequestion.Doesshedare(to)enterthedarkroom?\n3.注意情态动词need提问时的回答：-Needyougoyet?-Yes,Imust./No,Ineedn’t.4.need的被动含义：need/want/require/worth+doing也可以表示被动。needdoing=needtobedoneThishouseneedrepairing=(needtoberepaired).\nmust/havetomust和haveto都可以表示“必须”，但有几点区别：(1)must强调主观需要，而haveto强调客观要求。Hesaidthattheymustworkhard.(主观)Mybrotherwasill,soIhadtocallthedoctorinthemiddleofnight.（客观）Itisraininghardoutside,butIhavetoleavenow.(2)haveto可用于多种时态，而must一般用于现在时，其过去时与将来时分别由hadto与shall/willhaveto代替。(3)在回答must引起的问题时，如果是否定的答复，不能用mustn‘t，而要用needn’t或don‘thaveto，因为mustn’t表示“禁止”的意思。例如：“--Mustwedoitnow？”“—No,youneedn't.”\n(4)must用在肯定句中表示较有把握的推测，意为“一定”，否定推测用can’t.IfTomdidn’tleavehereuntilfiveo’clock,hecan’tbehomeyet.(5)must表示对现在的状态或现在正在发生的事情的推测，must后面接系动词be或行为动词的进行式。Youhaveworkedhardallday.Youmustbetired.Hemustbeworkinginhisoffice.\n典型例题：①Oneofthefewthingsyou___sayaboutEnglishpeoplewithcertaintyisthattheytalkalotaboutweather.A.needB.mustC.shouldD.can②--Hi,Tom.AnyideawhereJaneis?--She____intheclassroom.Isawhertherejustnow.shallbeB.shouldhavebeenC.mustbeD.mighthavebeenBC\n情态动词＋动词完成式情态动词＋动词完成式即“情态动词＋have＋done”，表示对过去的行为或动作进行推测、评论或判断。(1)musthavedonemusthavedone表示对过去某事的肯定猜测。其否定或疑问形式都用can(could)来表示。例如：Sincetheroadiswet,itmusthaverainedlastnight.Hecan'thavemissedtheway.Idrewhimamap.Thedictionaryhasdisappeared.Whocouldhavetakenit?\n(2)may/mighthavedonemay/mighthavedone表示推测过去某事“也许”发生了，may比might表示的可能性在说话人看来稍大些。例如：Ican'tfindmykeys.Imay/mighthaveleftthemattheschoolyesterday.(3)couldhavedone在肯定句型中，往往表示委婉的批评。本可以做什么而没做；有时也用作猜测。Youcouldhavetoldusearlier.Tomcouldhavetakenthedictionary.\n(4)oughtto/shouldhavedoneoughtnotto/shouldn’thavedoneoughtto/shouldhavedone和oughtnotto/shouldn’thavedone用于对已发生的情况表示“责备”、“不满”，分别表示“本应该…”和“本不应该…”。例如：1)Withalltheworkfinished，Ishouldhavegonetothepartylastnight.2)Yououghtnottohavemadefunofhim.Heisnottheoneyoulaughatbutlearnfrom.(5)needn'thavedoneneedn'thavedone表示过去做了某事，但没有做的必要，意为“本没必要……”。例如：Yonneedn'thavewakenmeup;Idon'thavetogotoworktoday.\n注：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，must最大，could其次，may更次之，might最小。例如：—IwonderhowTomknewaboutyourpast.—Hemust/could/may/mighthaveheardofitfromMary.\n典型例题：①--I’msorry.I___atyoutheotherday.--Forgetit.Iwasabitofcontrolmyself.A.shouldn’tshoutB.shouldn’thaveshoutedC.mustn’tshoutD.mustn’thaveshouted②Thankyouforallyourhardworklastweek.Idon’tthinkwe___itwithoutyou.A.canmanageB.couldhavemanageC.couldmanageD.canhavemanage③Whatapity.Consideringhisabilityandexperience,he___better.A.needhavedoneB.musthavedoneC.canhavedoneD.mighthavedoneBBD\n情态动词＋动词进行式情态动词＋行为动词进行式(即情态动词＋be＋doing)，表示推测或评论某动作现在是否正在进行。例如：(1)Hemustbeplayingbasketballintheroom.(2)Shemaybestayingathome.\n其他情态动词①usedto表示过去的习惯动作或状态(现在已不复如此)—Didyouusetogotheretoseeyourbrother?/Usedyoutogotheretoseeyourbrother?—Yes,Idid(usedto)./No,Ididn’t(usedn’t).　　②hadbetter表示“最好(做……)”Wehadbettergonow.其否定式为hadbetternot\n③wouldratherdo表示宁愿;wouldrather…than…表示宁愿…而不愿。IfIhaveachoice,Iwouldrathercontinuemystudyatthisschool.Iwouldratherstayherethangohome