高中英语情态动词讲解PPT课件

.,1,Grammar:Modalverbs,.,2,Howmanymodalverbsdoyouknow?,.,3,cancouldmaymightshallshouldmustwillwouldoughtto,havetodare(darent)need(neednt)usedto,表示推测,不表示推测,modalverbs,.,4,表示推测,一定，肯定must一定不，不可能cant,couldnt可能肯定句may,might,could否定句maymightnot疑问句can,could都可以+dosth.表示现在bedoing表示正在发生的动作havedone表示过去发生的动作,.,5,Hemusthaveacarnow.,.must表示推测时，可以推测现在/正在发生的动作/过去发生的动作。他一定有一辆车他一定在教室里做练习。他一定已完成了工作,Hemusthavefinishedthework.,Hemustbedoinghisexercisesintheclassroom.,.,6,一定不，不可能cantcouldntHecantbeathome.Hecouldnthavesaidsuchathing.他们一定不在图书馆读书。约翰是很聪明的，他应该不会叫他儿子那样做。,Theycantbereadinginthelibrary,Johnisveryclever.Hecannothavetoldhissontodothat.,.,7,可能肯定句could,may,might否定句maymightnot（可能不）疑问句can,could他可能正在睡觉。Thesestudentsmay/mighthaveseenthefilmbefore.否定句Theboymay/mightnotbewatchingTVathome.（现在）这个男孩可能没在家看电视,Hemay/mightbesleepingnow,.,8,疑问句Howcouldhehaveforgottensuchanimportantthing?这么重要的事他怎么能忘了呢？Itssolate.Wherecanshehavegone?天晚了，她可能去哪儿了呢？Canyouhaveleftthewatchathome?你会不会把表丢在家里呢？,.,9,Choosethebestanswerstocompletethefollowingsentences:1.Ithoughtyou_likesomethingtoread.SoIhavebroughtyousomebooks.A.oughtB.mightC.couldD.must2.ThatmanmustbeSarahshusband.-No,he_beherhusband.Sheisstillsingle.A.cantB.mustntC.maynotD.oughtto3.Peter_comewithustonight,butheisntverysure.A.mustB.mayC.canD.will,.,10,4.What_itbe?-It_beamailbox,foritismoving.It_beacar.A.can;cant;mustB.can;can;mustC.can;mustnt;mustD.must;mustnt;can5.Look,someoneiscoming.Guess_.-Jack.Hesalwaysontime.A.whocanitbeB.whohemayC.whohecanbeD.whoitcanbe,.,11,6.IsawMaryinthelibraryyesterday.-You_her.Sheisstillabroad.A.mustntseeB.canthaveseenC.mustnthaveseenD.couldntsee7.David,you_playwiththevaluablebottle,you_breakit.A.wont;cantB.mustnt;mayC.shouldnt;mustD.cant;shouldnt,.,12,表示能力,一表示能力can,could,beabletocan表示智力，体力方面的能力只能用现在或过去时。beableto通过努力克服困难作成事情,能用于各种时态。*was/wereableto:设法做成某事相当于managedtodosth.succeededindoingsth.。,.,13,can与beableto用法区别常与句子时态有关1.现在时比较1)表示”能力”时,beableto不用于第二人称,Youareabletodothework,Ithink.(X)改用cancan与感官动词feel,hear,see,smell,taste连用时,can显得可有可无,因而失去了情态动词的意义,这种情况下can不能用beableto代替e.g.,Wecanseebeautifulflowersandgreentreeshereandthere.Anyonecanseeitisofnouse.,.,14,3)can与某些表示意念的动词如：understand,remember,forget,hope,imagine,believe,suppose等连用时，同样没有情态动词的意义，也不可用beableto取代。e.g.Icantbelievetherearesomanytallbuildingsnowinmyhometown2.过去时比较was/wereableto意含”经过努力”“凭借才能”获得的”能力”常与”manageto”相通Theywereshortofmodernmachines,buttheywereabletocompletetheprojectintime.,.,15,二表示允许,can,could,may,mightmight,could表达更客气、委婉、礼貌的请求语气。Excuseme,couldyoutellmethewaytothebusstation?Couldyouhelpme?Youcangonowifyoulike.MayIsmokeintheroom?,.,16,三表示必须,oughtto/shouldhavetomust*haveto能用于各种时态,且有人称和数的变化.oughtto的否定式为oughtnotto或者oughtntto,.,17,1.should和oughtto大多数情况下，含义基本相同，should主要看主观看法，oughtto更多反映客观情况，在谈到法律，规定，义务时使用。如：youshouldtryyourbesttopasstheentranceexamanations.Weoughttogoandseehellen,butIthinkwehavenotime.Should还可以表示惊讶，出乎意料的意思Whyshouldhedosuchathing?,.,18,2.must与haveto的用法前者侧重于主观意念,后者则用于表示客观条件或义务,译为”只好”“不得不”e.g.,Hemustworktomakehisliving.Hehastobegforaliving.Must没有过去式,在单句中若是过去时,须用hadtoe.g.,Hebeggedfromdoortodoor,forhehadtodosotolive若在从句中,则可用must来表示过去e.g.,HesaidhemustmanagetoownanewhouseforEaster.,must用于疑问句，表示责备、抱怨的感情色彩，意思为“偏要，硬要、干嘛”；,.,19,四表示虚拟,shouldhavedone本应该做（而没做）shouldnothavedone本不应该做Heshouldnthavesaidsuchathing.他当时不应该说那种话。Weshouldhavestudiedlastnight,butwewenttotheconcertinstead这种句式也能用oughtto,.,20,neednothavedone没有必要做某事Ineednothavegotupsoearly.我本来不必要那么早起床的（事实上早已起床）Ineednothavewaitedforthetrainforanhour.我本来不必要等一个小时的火车。（事实上已经等了一个小时）,.,21,3.couldhavedone它表示“过去本来能够”实际上没能做。Ifyoucouldhavefinishedthetaskintime，youcouldhavebeenpromoted.如果你当时能如期完成那任务的话，你可能已提升了（实际上没有被提升）Icouldhavelaughedtohearhimtalklikethat.听他那样讲话，我差点笑出声来。,.,22,4.mighthavedone虚拟式表示与过去事实相反的假没结果。Ifshehadstartedalittleearlier，shemighthavebeenintimeforthetrain.如果她早点出发，她有可能及时赶上火车。(实际上没有早出发，便没有赶上火车)Itmighthavebeenbettertostopthen.如果那时就停止的话，也许比较好。,.,23,5wouldhavedone它表示的是与过去事实相反之假设的结果，意思是“当时就会了”而实际上没有IwouldhavehelpedyouifIhadknownofyourdifficulties.Ifithadntrainedyesterday,wewouldhavegoneclimbing.假如昨天没下雨，我们就去了。（实际上没有去）。,.,24,五其他情态动词用法情态动词dare,need通常用于否定句或疑问句Whodaredoit?Dareyougooutalone?dare,need还可用作行为动词，可以用于各种句式，后面可跟加to的不定式A.whodaredoit?B.Hedarestodoit.A.HeneedntdoitB.heneedstodoit上述句子中A句为含情态动词的句子，B句中dare.need均为行为动词,.,25,注意动词dare的某些特殊用法。1）固定句型Idaresay.我敢说我猜想以为Dontworry,sir.Idaresay,nobodywillcomeagain2)作为行为动词dare在否定句中后面的可以省略e.g:Hedoesntdare(to)gototheforestdoneatnight.Themanneverdares(to)doanythingwithouthisownerspermission.,.,26,5.dare“敢”，多用在否定或疑问句中。Thelittlegirldarenotspeakinpublic.小女孩不敢在公众面前说话。Dareyoucatchthelittlecat?你敢抓小猫吗?dare除用作情态动词外，更多的是当实义动词使用，用法同实义动词一样，要考虑人称，单复数，时态等。Doyoudaretowalkinthedark?你敢黑夜走路吗？Hedoesntdaretotelltheteacherwhathappenedthatday.他不敢告诉老师那天发生的事。,.,27,willI.表现在经常发生的情况e.g.,Themanwillgotoworkeveryday.(=Themangoestoworkeveryday后者更常用)Thedoorwontopen.II.表示“决心”“意愿”“可能”等e.gIfyouwillcometonight,hellmeetyou,Ithink.Thiswillbethebookyouarelookingfor.Willyoucomein?(=Willyoupleasecomein?),.,28,III.若表示过去，则用woulde.g.,Hewouldtakeawalkaftersupperwhenhelivedinthecountry.Hesaidhewouldhelp.表示“过去常常”除了用would，还可以用usedto，不过后者常常含有“现在不”之意。e.g.,Whenyoung,hewouldgooutforatriponSundays.(Nowmaybestilldoes)Whenyoung,heusedtogooutforatrip.(Butnowhedoesnt)此外，would表示“过去常常”时后面动词须是某种行为或动作，不能是静态动词。e.g.,Nearthevillage,there_beastream.A.wouldB.usedto,.,29,Would更多的用来表示语气而不是时态Will/wouldyoupleasedo.,Wouldyouliketodo.,Wouldyouminddoing.都表示建议、询问、请求等。e.g.,Would/Willyoumindopeningthewindows?Iwould/willdoanythingforyou,sir.有时甚至只能用would而不用wille.g.,Iwouldlike.Wouldyoulike.?Theywouldlove.Hewouldrather,.,30,shallI.表示询问或征求别人的意见看法用于一、三人称e.g.,ShallIopenthedoor?要我开门吗？Shallhestayhereforthenight?让他留下过夜吗？II.表示说话人的允诺，警告，命令，威胁等，用于二、三人称e.g.,Ifyouworkwell,youshallbewellpaidHesayshewontcome,butIsayheshall.Ifyougothereagain,youshalllosewhatyouvegot.,.,31,III表示规章，知识，预言等Eachcompetitorshallwearanumber.Therulesshallbeobeyed.,.,32,6反义疑问句,在反意疑问句中，当附属部分含有表示推测意义的must,cant时，疑问部分的助动词应与must,cant后面的动词在非推测情况下的用法保持一致。1.Hemustbeaworker,?2.Itmusthaverainedlastnight,?3.YoumusthavelearnedEnglishformanyyears,?4.Hecantbeateacher,?5.Shecanthavefinishedherhomework,?,didntit,haventyou,isnthe,ishe,hasshe,.,33,Homework,1.Finishexercises12afterclass.2.ReviewUnit13.,.,34,Practice:1.Noonepassedthemathematics.-Iguesswe_theexerciseslastnight.A.couldreviewB.shouldreviewC.mightreviewD.shouldhavereviewed2.She_thehosp