高三英语语法专题课件：情态动词和虚拟语气.ppt

高三英语语法专题课件：情态动词和虚拟语气,考点要览情态动词在一般疑问句中的问与答“情态动词+不定式完成式”的结构和用法“情态动词+bedoing”的意义“情态动词+havebeendoing”的意义情态动词shall与will,could表意愿时用法区别含情态动词must的句子的反意疑问句构成虚拟语气在其它从句中的用法及几种特殊句型,疑难点击部分情态动词的问与答“情态动词+不定式完成式”结构及意义“情态动词+bedoing”的意义“情态动词+havebeendoing”的意义情态动词shall,will和would表意愿时用法区别dare与need,usedto与would用法及区别must和haveto用法区别含有must句子的反意疑问句构成虚拟语气在if引导的条件状语从句中的用法虚拟语气在名词性从句中的用法几种常用的虚拟语气结构,(1)NeedI?Yes,youmust.No,youneednt.(2)MustI?Yes,youmust.No,youneednt.(3)MayI?Yes,youmay.(=Yes,certainly/ofcourse.)No,youmaynot.(=No,youcant/mustnt.),(4)ShallI.?Yes,please.No,thanks.No,youneednt.（委婉）No,youcant.（反对）No,youmustnt.（禁止）(5)MightI?Yes,youcan.No,youcant.,(1)musthavedone（语气肯定）“过去一定”表示对过去情况极大把握的推测。Ididnthearthetelephone,Imusthavebeenasleep.我没有听到电话铃声，我一定是睡着了。(2)should/oughttohavedone“本来应该”“按理该”表示责备，惋惜。Theplantisdead,Ishouldhavegivenitmorewater.植物死掉了，我本应该给它浇更多的水的。(3)may/mighthavedone（语气不肯定）“过去可能”表推测。,Hemighthavegivenyoumorehelp,eventhoughhewasverybusy.他本应可以给你更多帮助，即使他非常忙。(4)cant/couldnthavedone（语气肯定）（否定句和疑问句）“过去不可能”对过去发生的事的不肯定或怀疑。HecanthavestudiedEnglishbefore.他以前没有学过英语。(5)couldhavedone本来能做却未做，表责备。mighthavedone本来可以做却未做，表责备。,Hecouldhavewalkedtothestation,itwassofar.我们本应走着去火车站，这么近。(6)neednthavedone已做了某事，但没有必要。shouldnthavedoneoughtnttohavedone本来不该做却做了，表责备，惋惜。Ineednthaveboughtthebook.我没有必要买这本书。Tomoughtnottohavetoldmeyoursecret.汤姆本不该把你的秘密告诉我。,“情态动词+bedoing”表推测，“应当正在可能正在”。Theymustbewaitingforyou.他们一定在等你。（1）间或此结构可表示“即得，将要”这类意思。Imustbeleavingnow.我得立刻离开了。（2）间或表示老是在做某事。Whymustyoualwaysbefindingfaultwiththatgirl?你为什么总是和这姑娘过不去？,“情态动词+havebeendoing”表推测有“应当一直在”等含义。例:Theycanthavebeenworkingforthatlonglastnight.昨晚他们不可能工作那么久。Yourmothermusthavebeenlookingforyou.你妈妈一定一直在找你。,询问对方意愿，表白说话人的意愿。向对方提出请求时（第二人称）用will/would。当shall用于第三人称疑问句时，表示征求对方意见或请求指示。,dare和need作情态动词时不用于肯定句；作实义动词时不受限制。usedto表示“过去常干”，但现在不干了，常与like,be等状态动词连用。would(do)表示“过去常干”，但不强调现在如何，并带有赞扬、厌恶等感情色彩。,must表示说话人的主观看法，而haveto表示客观的需要；mustnt表示为“决不能”“禁止”“一定不要”，而donthaveto表示“不必要”。（英国英语中常用neednt）,（1）must表示“必要”“必须”时，附加部分用mustnt?或者说neednt?（2）must用于否定形式mustnt时，附加问句部分用may或must。（3）must表示“推测”意义时，要根据具体情况而确定。例如：Hemustknowthesecret,doesnthe?他一定知道这个秘密，不是吗？Hemustbeateacher,isnthe?他一定是个老师，不是吗？Youmusthaveseenhimoffyesterday,didntyou?你昨天一定是看见他离开了，不是吗?YoumusthavestudiedEnglishbefore,haventyou?你以前一定是学过英语，不是吗？,（1）若与现在事实相反从句形式为：If+主语+动词过去式（be动词一般为were）主句形式为：主语+would/should/could/might+v.（2）若与过去事实相反从句形式为：If+主语+had+done主句形式为：主语+would/should/could/might+have+done,（3）若与将来事实相反从句形式为：If+主语+动词过去式should+v.wereto+v.主句形式为：主语+would/should/could/might+v.,（1）在某些动词的宾语从句中，形式是“（should）+动词原形”。常见动词有：一个坚持（insist）；两个命令（order,demand）；三个建议（advise,suggest,propose）；四项要求（demand,require,request,ask）。（2）作某些词的同位语和表语从句时，形式是：“（should）+动词原形”。常见的名词有：advice,idea,order,demand,plan,proposal,suggestion,request,opinion等。（3）下列主语从句中用“（should）+动词原形”Itisnecessary(important,natural,strange,surprising,etc)thatItisapity(ashame,nowonderetc)thatItissuggested(decided,ordered,requested,etc)that,（1）用butfor,without等介词短语表达条件。例如：Butforyou,wecouldnthavecarriedouttheplan.要不是你的话我们（当时）无法实行那项计划。（2）Itstimethat+动词过去式should+动词原形“该做的时候了”例如：Itistimewegotup.该是起床的时间了Itis(high)timeweshouldgetup.该是我起床的时间了（3）wouldrather(that)动词过去式（与现在或将来相反）had+done了,“宁愿（而不）”（与过去事实相反）例如：Iwouldratherhestayedathomenow.我宁愿他现在在家里hestayedathometomorrow.我宁愿他明天在家里.hehadstayedathomeyesterday.我宁愿他昨天在家里(4)wish=ifonly+从句（从句谓语动词有三种形式）would(could,might)+动词原形（与过去事实相反）动词过去式（与现在事实相反）had+过去分词或用couldhave+过去分词（与过去事实相反）,例如：Iwish(ed)Icould(would,might)gotothemooninaspaceshiponeday.我希望有一天我能乘坐宇宙飞船登上月球.Iwish(=Ifonly)hevisitedusnow.要是他现在能来看望我.Iwish(Ifonly)hehadvisiteduslastnight.=Iwish(Ifonly)hecouldhavevisiteduslastnight.要是他昨晚能来看望我们就好了.(5)asif(thought)（方式）“好像，仿佛”+动词过去式（与现在事实相反）过去进行式（与现在正在进行相反）had+done（与过去事实相反）could/might/would+动词原形（与将来事实相反）,例如：Itlooksasif/thoughsomeonewererunning.好象有人在跑步.shehadntdonethat.她好象没有做那样的事sheweretwoyearsyoungertoday.她今天看起来好象年轻了两岁.shewouldliveanother100years.她好象还能活100岁.（6）有时候，条件从句表示的动作和主句表示的动作发生的时间是不一致的（如一个是过去发生的，一个是现在发生的），这这时动词的形式要根据表示的时间来调整。,例如：IfIhadfollowedthedoctorsadvice,Iwouldbebetternow.如果我听了医生的建议,我现在可能就好多了.Ifyouhadworkedhardthen,youwouldbeintheuniversitynow.如果那时你努力一些,你现在就上大学了.Ifthedoctorhadcomesoonerlastnight,thepatientwouldbealivenow.如果医生昨晚能早来一会儿,病人现在可能就活下来了.（7）evenif/though引导让步状语从句，从句中用may/might+动词原形，may或might可省略，表示与现在情况相反；从句用过去时，表示与过去情况相反；类似的词还有：though/asthough/solongas/nomatter,matterwh-/whatever/whenever/whoever等。Howeverdangerousitmightbe,hewouldhaveatry.无论多危险，他都要试一试。EventhoughIhadbeenverybusythen,Iwouldhavehelpedyou.即使我当时很忙，我还是会帮助你的。（8）表示祝愿或诅咒的祈使句Mayyousucceed!祝你成功！Godblessyou!愿上帝保佑你！（9）过去分词短语表示条件Givenmoretime,wecouldhavedoneitbetter.倘若给我们会把它做得更好。（10）通过上下文表示条件Suchmistakencouldhavebeenavoided.这种错误本来是可以避免的。,1.Excuseme,butIwanttouseyourcomputertotypeareport.You_havemycomputerifyoudonttakecareofit.A.shantB.mightnotC.needntD.shouldnt2.Excuseme.IsthistherightwaytotheSummerPalace?Sorry,Iamnotsure.Butit_be.A.mightB.willC.mustD.can3.IlltellMaryabouthernewjobtomorrow.You_herlastweek.A.oughttotellB.wouldhavetoldC.musttellD.shouldhavetold,4.Iheardtheywentskiinginthemountainslastwinter.It_truebecausetherewaslittlesnowthere.A.maynotbeB.wontbeC.couldntbeD.mustntbe5.Hehesitatedforamomentbeforekickingtheball,otherwisehe_agoal.A.hadscoredB.scoredC.wouldscoredD.wouldhavescored6.Writetomewhenyougethome._.A.ImustB.IshouldC.IwillD.Ican,7.IhearyouvegotasetofvaluableAustraliancoins._Ihavealook?Yes,certainly.A.DoB.MayC.ShallD.Should8.Whatwouldhavehappened_,asfarastheriverbank?A.BobhadwalkedfartherB.ifBobshouldwalkfartherC.hadBobwalkedfartherD.ifBobwalkedfarther9.Sorry,Imlate.I_haveturnedoffthealarmclockandgonebacktosleepagain.A.mightB.shouldC.canD.will,10._besenttoworkthere?A.WhodoyousuggestB.WhodoyousuggestthatshouldC.DoyousuggestwhoshouldD.Doyousuggestwhomshould11.Withbetterequipment,we_thejobevensooner.A.wouldfinishB.mightfinishC.couldhavefinishedD.hadfinished12._thefog,weshouldhavereachedourschool.A.BecauseofB.InspiteofC.IncaseofD.Butfor,13.Theyoungmaninsistedthathe_nothingwrongand_free.A.did;setB.haddone;shouldbesetC.do;besetD.haddone;mustbeset14.Theymusthaveherethedaybeforeyesterday,_?A.mustnttheyB.werenttheyC.haventtheyD.hadthey15.DoyoustillrememberthedaywhenwewenttotheGreatWall?Icantrememberitwell,but_sometimelastautumn?A.mightitbeB.couldithavebeenC.coulditbeD.mustithavebeen,