高三英语语法情态动词(课件)

情态动词,ThebasicusesofModalVerbs,可兼做行为动词的情态动词：need、dare,情态动词(+动词原形),行为动词,.,need,dare,1.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,noone,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;(sb.)needtododaretodo(sth.)needtobedone(sth.)needdoing,一、1.can,could为can的过去式；语气更委婉,can表示习惯能力，而beableto表示经过努力而做成了某事。2.在否定结构中，二者可以互换。,1.在否定、疑问句中表示“对过去发生行为的可能性猜测。2.在肯定句中表示“本来可以做而未做”,Thedoorwaslacked.Shecouldnthavebeenathome.Youcouldhavebeenmorecareful,butyouweresocareless.,二、1.may,might为may的过去式；语气更委婉,1.在否定、肯定句中表示对过去动作的推测“也许是”2.might+have+p.p表示虚拟，表“劝告、责备之意。”,eg.1.Shemaybestillwaitingforus.2.MayIcomein?3.Mayyouhaveahappyholiday.,eg.1.Hemighthavespokentoheryesterday.2.Youmighthavetoldmeearlier.,三、1.must,表示肯定的猜测,但只用于肯定句，而mustnt表示“禁止、不准”,Must表示主观Haveto表示客观需求Havegotto多见于口语,3.must+have+p.p,对过去事情的肯定猜测。,Eg.Theroadidwet.Itmusthaverainedlastnight.,四、1、shall/should,2、shall/should+have+p.poughtto,表示本应该做而未做。,should为shall的过去式语气更委婉,eg.Youshouldhavebeenfiveminutesago.,五、1、will/would,1、would后只能接表示动作的动词。,2、usedto则还可以接表示状态的动词。eg.Heusedtobeaworker.,补充说明,1.、情态动词的过去式与原形相比，多点礼貌，少点冒昧，语气更为委婉。,情态动词在一般疑问句中的回答：Canyousing?MayIcomein?MustIhandinthebooknow?NeedIfinishitnow?,表示推测情态动词的重要用法.,肯定的推测可能的推测否定的推测疑问的推测,must/should,对将来对现在对过去,情态动词,may,might,cant,couldnt,can,could,+V.+V.+havedone常见mustbe+bedoing,+V.+V.+havedone+bedoing可以用not表示“可能不”,+V.+V.+havedone+bedoing,+V.+V.+havedone+bedoing,Choosethebestanswers:1.Ithoughtyou_likesomethingtoread.SoIhavebroughtyousomebooks.A.oughtB.mightC.wouldD.must,2.ThatmanmustbeSarahshusband.-No,he_beherhusband.Sheisstillsingle.A.cantB.mustntC.maynotD.oughtto3.Peter_comewithustonight,butheisntverysure.A.mustB.mayC.canD.will,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,6.IsawMaryinthelibraryyesterday.-You_her.Sheisstillabroad.A.mustntseeB.canthaveseenC.mustnthaveseenD.couldntsee7.David,you_playwiththevaluablebottle,you_breakit.A.wont;cantB.mustnt;mayC.shouldnt;mustD.cant;shouldnt,8.SusanrefusestomarryJacknow.She_hermind.A.mustchangeB.shouldhavechangedC.musthavechangedD.wouldhavechanged,9.Sue_cometogetherwithustonight,butsheisntverysureyet.A.mustB.mayC.needD.will,10.AuntMargaret_thetrain,otherwiseshewouldhavearrivedherebynow.A.musthavemissedB.shouldhavemissedC.hadmissedD.mightmiss,典型错误,1.Hemustntbeintheclassroom.(),cant,2.Youmightleavethebagonthebed.(),mighthaveleft,3.Youmusthaveseenthefilmlastweek,havetyou?(),didntyou,4.LiMingmusthavebeentoJapan,didnthe?(),hasnthe,情态动词+have+done”表“本来”使用情形分析,一、shouldhavedone过去本来应该（而实际上并没有)shouldnothavedone本不应该而实际上却已经”如：1、Weshouldhavestudiedlastnight,butwewenttotheconcertinstead.我们昨晚本应学习的，但我们却去看音乐会了。（实际上没有学习）,二、couldhavedone它表示过去本来能够实际上没能做。如1、Icouldhaverun100metresin12seconds.我本来能用12秒钟完100米的.（实际上没能）2、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）,三、neednothavedone它表示过去已做的事，事实上没有必要。如，1、Ineednothavegotupsoearly.我本来不必要那么早起床的（事实上早已起床）2、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）问题:,wouldhavedone在什么情况下使用呢?,四、wouldhavedone用在虚拟语气中表示与过去事实相反之假设的结果，常与if的条件句连用。1、IwouldhavehelpedyouifIhadknownofyourdifficulties.要是我当时知道你们的窘境，我就会帮助你了（而实际上没有帮助你）2、Ifithadntrainedyesterday,wewouldhavegoneoutforawalk.假如昨天没下雨，我们就去散步了。（实际上没有去）。,Practice,1.MrWhite_at8:30forthemeeting,buthedidntturnup.A.shouldhavearrivedB.shouldarriveC.shouldhavehadarrivedD.shouldbearriving,2.Ifhehadbeenhereyesterday,he_thispopstar.A.wouldmeetB.wouldhavemetC.metD.