2019高考英语语法精讲 情态动词和虚拟语气

情态动词与虚拟语气※情动+havedone※hadbetter※※※※※※一、9大情态动词的基本用法1.can/could(1)表示能力(could常用于表示过去的能力)(2)表示理论上的可能性,“有时候可能会”(用在肯定句中)(3)can’t表“不能/不可能”)2.may/might表示请求、允许、许可。3.must(1)表“必须;应该”,表有把握的推测,意为“准是、一定”4.shall(1)用于第一、三人称的疑问句中,表征求对方的意见(2)用于第二、三人称的陈述句,表说话人给对方的命令、警告、允诺或威胁;此外,表示法律、条文中规定“必须……”时也用shall(2)must’t禁止mustn.必须做的事；必不可少的东西Mayn.五月表祝福May+名+动Wish+名+名5.should(1)表示劝告和建议,作“应该”讲(3)用在if条件句中,表示可能性很小,但也不是完全不可能6.will/would(1)用于表示意志或意愿(2)表示“请求;建议”。用would比will委婉、客气些(2)表示惊讶、意外等情绪,意为“竟然”(3)表示习惯,would可表示过去的习惯性动作7.need表“需要;必要”,也可做实意动词needtodo8.dare表“敢;敢于”,Idaresay是习惯说法,意为“我想,大概”也可做实意动词daretodo9.oughtto表示义务,意为“应当”,否定式为oughtnottodo。易混词(组)用法比较*Mayyouliveahappylife!*Ipromisedheshallgetapresentforhisbirthday.*Ithasbeenannouncedthatcandidatesshallremainintheirseatsuntilallthepapershavebeencollected.*Itissurprisingthatyoushouldnotknowit.*Hewouldgetupearlywhenhelivedinthecountry.三、“情态动词+havedone”的用法1.对过去发生的事情或状态进行推测musthavedone(过去)一定……;语气比较肯定;用于肯定句may(might)havedone(过去)可能……;语气不确定;用于肯定句和否定句can(could)havedone用于否定句和疑问句,表示怀疑或不确定2.表示“与过去事实相反”couldhavedone过去本可以做某事但实际上没做needn’thavedone过去本不必做某事但实际上做了oughtto/shouldhavedone过去本应该做某事但实际上没做oughtn’tto/shouldn’thavedone过去不应该做某事但实际上做了mighthavedone过去本可以做某事但实际上没做*Lookingatthelargeemptyapartment,IbegantobeawareofhowlonelymymothermusthavebeeninBrazilherself.*Theboymighthaveknownthetruth,butIamnotquitesure.*Youcan’thaveseenhimjustnow.Hehasbeenabroadfornearlyamonth.*Hecouldhavegoneonregrettingit,astoomanyofusdo.*Youneedn’thaveworkedthatlatelastnight.Itwasharmfultoyourhealth.*Yououghttohavedonethisexercisemorecarefully.*Youmighthavegivenhimmorehelp,thoughyouwereverybusythen.【题组训练】用适当的情态动词填空(必要时用否定形式)世纪金榜p1471.You_______havetoldJimanythingaboutit.Itwasnoneofhisbusiness.2.Itwasreallyannoying;I________getaccesstothedatabankyouhadrecommended.needn’tcouldn’t3.You_____beCarol.Youhaven’tchangedabitafteralltheseyears.4.MrWhite______havearrivedat8:30forthemeeting,buthedidn’tshowup.5.—Mummy,Iclimbedtogettheteddybearfromthetopoftheshelf.—Mygoodness!You______havehurtyourself.mustshouldmight1.Youdidn’tletmedrive.Ifwe______inturn,you_____sotired.A.drove;didn’tgetB.drove;wouldn’tgetC.weredriving;didn’tgetD.haddriven;wouldn’thavegot高考题C2.Ididn’tseeyoursisteratthemeeting.Ifshe_____,shewouldhavemetmybrother.A.hascomeB.didcomeC.cameD.hadcome3.Whatwouldhavehappened,______,asfarastheriverbank?A.BobhadwalkedfartherB.ifBobshouldwalkfartherC.hadBobwalkedfartherD.ifBobwalkedfartherDC5.ItishardformetoimaginewhatIwouldbedoingtodayifI______inlove,attheageofseven,withtheMelindaCoxLibraryinmyhometown.A.wouldn’thavefallenB.hadnotfallenC.shallfallD.weretofallB4.Hehesitatedforamomentbeforekickingtheball,otherwisehe____agoal.A.hadscoredB.scoredC.wouldscoreD.wouldhavescoredD类别从句谓语动词主句谓语动词与现在事实相反过去式(be用were)should/would/could/might+动词原形与过去事实相反had+过去分词should/would/could/might+have+过去分词与将来事实相反过去式(be用were)should/would/could/might+动词原形should+动词原形wereto+动词原形(一)虚拟语气if用于条件状语从句中*Ifmybrotherwerehere,everythingwouldbeallright.*Ifitshouldrainthisafternoon,thebasketballmatchwouldbeputoff.*Ifyouhadtakenmyadvice,youwouldnothavefailedintheexam.2.if虚拟条件句中的省略与倒装如果if虚拟条件句从句中含有were/had/should,有时可把if省略,把were/had/should提到主语之前形成倒装;若为否定形式,not不可提前。*Hadhecaughtthemorningtrain,hewouldnothavebeenlateforthemeeting.3.错综时间条件句有时条件句的动作与主句动作发生的时间不一致,这时动词的形式应根据它们各自表示的时间加以调整。*Ifwehadbookedatableearlier,wewouldn’tbestandinghereinaqueue.(if条件句是对过去的虚拟,而主句是对现在的虚拟。)4.含蓄条件句(1)有时假设的情况不用条件句表达,而是用butfor,without等介词(短语)或上下文来表示。*Wewouldn’thavefinishedtheprojectontimewithoutyourtimelyhelp.(2)用otherwise,or等暗示后文与前面的情况相反,从而引出后文的虚拟语气。*Myparentslentmethemoney.Otherwise,Icouldn’thaveaffordedthetrip.(3)虚拟条件通过but暗示出来,结构为“虚拟情况+but+真实情况”。*Iwouldhavetakenpartinthesportsmeeting,butIwasillthatday.(二)目的状语从句中虚拟语气的用法forfearthat/incase+从句:从句谓语用should+动词原形,意为“以防,万一”。*Wegotupearlyforfearthatweshouldmisstheearlybus.(三)方式状语从句中虚拟语气的用法asif/asthough+从句:(1)与现在事实相反,从句用一般过去时;(2)与过去事实相反,从句用过去完成时;(3)与将来事实相反,从句谓语用would/could/might+动词原形。*ShespeaksEnglishasif/asthoughshewereanativeofNewYork.二、虚拟语气用于名词性从句中1.主语从句中的虚拟语气在“Itis+important/necessary/natural/strange/essential/vital/apity+that...”句型中,谓语动词用(should+)动词原形。*It’svitalthatwe(should)takeoursafetydrivingalongtheroadseriously.2.宾语从句中的虚拟语气(1)在wouldrather(that)后的宾语从句中,从句的谓语动词如果表示现在或将来要发生的动作,从句用一般过去时;如果表示过去发生的动作,从句用过去完成时。*I’dratherhehadgonetotheseasidewithmethedaybeforeyesterday.要是他前天和我一起去海边就好了。(2)表示“建议,命令,要求”等意义时,宾语从句用“(should+)动词原形”。①坚持:insist;②命令:order,command;③建议:advise,suggest,propose,recommend;④要求:request,require,demand,ask。*Hesuggestedthatwe(should)startoffearlythenextday.【点津】①suggest意为“表明,暗示”时,宾语从句不用虚拟语气。*Thesmileonhisfacesuggestedthathewassatisfiedwithourwork.②insist意为“坚持说”时,宾语从句不用虚拟语气。*Themaninsistedthathehadneverstolenmoney.(3)wish后宾语从句中的虚拟语气虚拟语气从句谓语动词与现在事实相反过去式(be动词一般用were)与过去事实相反had+过去分词与将来事实相反would/could+动词原形*Iwish(that)Iwereabirdandcouldflyfreelyinthesky.*Iwish(that)Ihadmetthatscientistyesterday.3.表语从句和同位语从句中的虚拟语气(1)在suggestion,proposal,order,plan,idea,request,advice等名词后的表语从句和同位语从句中要用虚拟语气。谓语动词构成是“(should+)动词原形”。*Hegaveordersthattheguests(should)behospitablyentertaine