情态动词和虚拟语气----ByBringEnglishcan,couldmay,mightwill,wouldshall,shouldmust,needhaveto,oughttocan’t,maynotmustn’t,needn’tdon’thavetoshouldn’t,shan’tbeabletodare情态动词1.can,could表示能力HecanspeakEnglishverywell.Hecoulddrawverywellwhenhewasfive.表示许可Youcanusemycomputernow.Youcan’teatinclass.表示请求Canyoutellmethewaytothepostoffice?CouldyoushowmethewaytotheBeihaiPark?表示猜测Generally,sheisaquietgirl.Butsometimesshecanbetalkable.Someoneisknockingatthedoor.Whocanitbe?Itcan’tbeMr.Zhang.Hehasgoneabroad.Thehuntershavebeenlostfordays.Theycouldstarve.表示惊讶Howcanshebelateforclass?Sheisalwaysontime.2.may,might请求许可MayIhavealookatyournewmobilephone?表示可能Themanovertheremaybeyournewteacher.Hemightcomeherebytrainorbyair.3.will,would表示意愿、倾向Onrainydays,shewillsitbythewindowandwatchtherainforhours.Hewaspoor,buthewoulddressupasarichman.表示请求Willyoupleasegiveyourseattotheoldlady?Wouldyouliketojoinusfordinner?4.shall用于第一人称，表示将要Ishallgowithyounexttime.用于第一人称，表示征求意见ShallIputthebookbackontheshelf?/Shallwegooutforawalk?用于第二、三人称，表示许诺、义务、规定、威胁Youshallgetanewmobilephoneifyoupasstheexam.Everyoneshallwaitinlinewhentheybuytickets.Accordingtotheagreement,theinterestshallbedividedequallyamongthethreeinvestors.5.should表示建议（应该）Youshouldliedownandhavearest.表示猜测It'sseveno'clock.Mr.Lishouldbethere.Youhavepracticedalot.Youshouldn'thaveanytroubleinpassingthetest.表示惊讶It'ssurprisingthatsuchaprettygirlshouldbeathief.6.must表示必需Wemustfinishourworkbynoon.表示猜测Theremustbesomethingwrong.表示责怪（偏偏，非得）Tom,mustyouplaythepianoatthistime?MycarmustbreakdownwhenIwashurryingtowork.7.need表示需要（否定或疑问句）Youneedn'tgotoschooltoday.用作实意动词Youdon'tneedtogotoschooltoday.8.haveto表示必需，不得不Youhavetofinishyourworkbynoon.9.oughtto表示应该Yououghttohandinyourhomeworkbeforeschoolisover.10.dare表示敢Howdareyousaythattoyourmother?Shedaren'tgooutinthedark.Hedarednotasktheteacherforhelp.用作实意动词Hedarestoswimacrosstheriverbyhimself.Doeshedaretoswimacrosstheriverbyhimself?Hedoesn'tdaretoswimintheriver.注意各种否定式：1.can'tIcan'tplayanymusicalinstrument.(不能)Itcan'tbepossible.It'ssorediculous！(不可能)2.mustn'tYoumustn'tsmokeinpublicplaces.(千万别)3.maynotThatmaynotbetrue.(可能不)4.needn't(没必要)5.don'thaveto(没必要)6.shouldn't(不应该)情态动词+havedone1.musthavedone一定做过某事2.may/might/could(not)havedone可能(没)做过某事3.can'thavedone不可能做过某事4.should(not)havedone本(不)应该做某事5.needn'thavedone本没必要做某事6.ought(not)tohavedone本(不)应该做某事7.would(not)havedone本(不)会做某事虚拟语气一.在条件句中的用法if从句动词主句动词与现在事实相反过去时（be用were）would/should/could/might+动词原形与过去事实相反过去完成时（haddone）would/should/could/might+havedone与将来事实相反1.过去时（be用were）2.should+do3.were+todowould/should/could/might+动词原形1.IfIwereyou,Iwouldasktheteacherforadvice.Ifheknewthetruth,hewouldtellyou.2.Ifyouhadcomeearlier,youwouldhavemetthefamousstar.Shewouldn'thavebeensoangryifyouhadapologizedtoher.3.Ifitweretosnowthisevening,theywould/should/could/mightnotgoout.Ifitshouldbreakdownwithinoneyear,wewouldrepairitatourexpense.Ifyouwentthere,Iwould/should/could/mightgowithyou.需要注意的问题1.错综条件句Ifyouhadfollowedmyadvice,youwoulddoitbetternow.IfIwereyou,Iwouldn'thavemissedthefilmlastnight.2.倒装句（省略if）Weresheolder,shewoulddoit.Shouldhecome,tellhimtoringmeup.Hadwetakenthetaxi,wewouldn'thavebeenlateforthemeeting.二.介词短语等代替条件从句Withoutair,therewouldbenolivingthings.Butforyourhelp,wewouldn'thavefinishedthetaskontime.三.根据上下文判定1.Iwouldhavecometoyourparty,butIwastoobusylastnight.2.Iwastoobusylastnight,otherwiseIwouldhavecometoyourparty.3.Youweredrivingtoocarelessly,otherwiseyouwouldn'tbeinhospitalnow.四.在其他从句中的虚拟语气1.IwishIhadmyowncompany.IwishIwouldtravelinspacesomeday.IwishIhadknownyouearlier.2.Iwouldratheryoucameheretomorrow.IwouldratherIhadn'tseenthefilm.3.Hetalksasifhekneweverything.Hetalksasifhehadbeentothemoon.4.Hesuggested/ordered/requested...that...(should)do...5.Itisimportant/strange/necessarythat...(should)do...6.Itiscommanded/suggested/requiredthat...(should)do...7.Therequirementisthat...(should)do...8.Weallagreedtothesuggestion/request/adviecethat...(should)do...
