情态动词与虚拟语气一、can/may/must/need问句的回答方式疑问句式肯定句式否定答式Can/Couldyoudosth.Yes,I/we/can/couldNo,Iwecan’t/couldn’tMayIdosth.?Yes,youmay.No,youmustn’t/maynot.MustI/wedosth.?Yes,youmust.Noyouneedn’t/don’thaveto.NeedIdosth.?Yes,youmust.No,youneedn’t/don’thaveto.二．.情态动词的基本用法1.can(could)1）表示能力，could主要指过去时间。Twoeyescanseemorethanone.Couldthegirlreadbeforeshewenttoschool?2）表示可能（理论上或是逻辑判断上）。Thetemperaturecanfallto–60℃,thatis60℃belowfreezing.Hecan’t(couldn’t)haveenoughmoneyforanewcar.Youmustn’tsmokewhileyou’rewalkingaroundinthewood.Youcouldstartafire.3）表示允许。CanIhavealookatyournewpen?Heaskedwhetherhecouldtakethebookoutofthereading—room.4）表惊异、怀疑、不相信等态度。主要用于否定句、疑问句或感叹句中。Wherecan(could)theyhavegoneto?Hecan’t(couldn’t)beoversixty.Howcanyoubesocareless?5）比较委婉客气地提出问题或陈述看法。Can(Could)youlendmeahand?I’mafraidwecouldn’tgiveyouananswertoday.2.may(might)1）表允许，might可以指过去时间，也可指现在时间，语气更委婉。Youmaytakewhateveryoulike.HetoldmethatImightsmokeintheroom.May(Might)Iaskforaphotoofyourbaby?在回答以may引起的问句时，多避免用这个词，而用其它方式，如Yes,please./Certainly./Pleasedon’t./You’dbetternot./No,youmustn’t.等，以免显得太严峻或不客气。2）表可能（事实上）。可以指过去时间，也可以指现在时间，但语气更加不肯定。Hemaybeathome.Shemaynotknowaboutit.Hewasafraidtheymightnotagreewithhim.Theymightbehavingameeting,butI’mnotsure.3.must1）表示义务。意为“必须”（主观意志）。Wemustdoeverythingstepbystep.Youmustn’ttalktoherlikethat.--Mustwehandinourexercise—booksnow?--No,youneedn’t./No,youdon’thaveto.（这种情况下，一般不用mustn’t）2）表示揣测。意为“想必、准是、一定”等，只用于肯定句。Hemustbeill.Helookssopale.She’swearingadiamondnecklace.Shemusthavealotofmoney.4.shall1）表征询意见，用于第一、第三人称疑问句。ShallIgetyousometea?Shalltheboywaitoutside?Whatshallwedothisevening?2）表说话人的意愿，有“命令、允诺、警告、决心”等意思，用于第二、第三人称陈述句。YoushalldoasIsay.（命令）Youshallhavemyanswertomorrow.（允诺）Heshallbesorryforitoneday,Itellyou.（警告）Nothingshallstopusfromcarryingouttheplan.（决心）5.will1）表意愿，用于各种人称陈述句。Iwilldoanythingforyou.Noneissoblindasthosewhowon’tsee.Ifyouwillreadthebook,I’lllendittoyou.2）表请求，用于疑问句。Willyouclosethewindow?It’sabitcold.Won’tyoudrinksomemorecoffee?3）表示某种倾向或习惯性动作。Fishwilldieoutofwater.Thedoorwon’topen.Theboywillsittherehourafterhourlookingatthetrafficgoby.6.should1）表义务。意为“应该”（某件事宜于做），用于各种人称。Youshouldbepolitetoyourteachers.Youshouldn’twasteanytime.2）表推测，意为“想必一定、照说应该、估计”等。Thefilmshouldbeverygoodasitisstarringfirst—classactors.Theyshouldbehomebynow.7.would1）表意愿。Theywouldnotlethiminbecausehewaspoorlydressed.IsaidIwoulddoanythingforyou.2）表委婉地提出请求、建议或看法。Wouldyoulikeanotherglassofbeer?Wouldyoumindcleaningthewindow?Theywouldn’thaveanythingagainstit.3）表过去反复发生的动作或过去的一种倾向。Everytimeshewasintrouble,shewouldgotohimforhelp.8.oughtto1）表义务，意为“应该”（因责任、义务等该做），口气比should稍重。Youarehisfather.Yououghttotakecareofhim.Yououghtn’ttosmokesomuch.2）表推测，暗含很大的可能，语气较弱。HanMeioughttoknowhistelephonenumber.There’safinesunset;itoughttobeafinedaytomorrow.9.used...
