情态动词 课件.ppt

情态动词,can的用法may的用法must的用法,can的用法,1.Icanliftthestone.2.Youcanborrowmybiketomorrow.3.Canitbetrue?4.Itcantbetrue.,.1.能力2.许可3.猜测（用于疑问句、否定句）,.can与beableto的区别,1.HesayshewillbeabletobehomeforChristmas.2.Iwasabletohelpyouyesterday.3.Thisproblemcanbesettledatonce.,can有现在时、过去时；可用于被动语态。beableto有各种时态；指某一次动作；不可用于被动语态。,.常用句型1.couldhavedone2.can/couldhavedone?3.cant/couldnthavedone,1.Shecouldhaveexplainedthematter.2.Canshehavetoldalie?3.Wherecan/couldhehavegone?4.Hecant/couldnthavesaidthat.5.Shecant/couldnthavebeenathomeallthistime.,本来能够做可能做过吗？不可能做过,may的用法,1.Youmaygohomenow,Susan.2.Youmaynotsmokeintheclassroom.3.MayIsitdown?Certainly./Yes,please./Whynot?/Sure.No,Iamsorry./Imafraidyoucant.4.Imayborrowthisbook,mayntI?,。1.许可,表示许可时，无甚区别，may较正式，can较口语化。,5.MayIspeaktoyouforamoment,professor?6.CanIhaveacupoftea,mother?,2.猜测、可能性（用于肯定句中）,1.Thestorymayormaynotbetrue.2.Canthatbetrue?Maythatbetrue?3.Hecantknowthetruth.Hemaynotknowthetruth.,他不可能知道真相。他可能不知道真相。,。mayhavedone可能做过,1.shemayhavemissedthebus.2.Itmayhavedrizzledduringthenight.,must的用法,1.Youmustgetupmuchearlier.2.Youmustnotspeakillofothers.3.Mustwewashthedishesatonce/Yes,youmust.No,youneednt./youdonthaveto.4.Ourboymustdotheoppositetowhatweordered.5JustwhenIwasbusy,shemustcomeandchatter.6.Its10oclock.Mymothermustbeangry.7.Wethoughtourteachermustbejoking.,。1.必须、一定2.偏偏3.猜测（用于肯定句）,。musthavedone肯定做过,1.Itmusthaverainedlastnight.Thegroundiswet.2.Nooneanswersthephonebell.Theymusthavegoneout.,。构成的反意疑问句,1.Wemustworkhardatmaths,_?2.Youmustrealizethatwecantallowsuchbehavior,_?3.Theymusttothereatonce,_?4.Thehousesmustbecleanifthereareguests,_？,neednttwe,mustntyou,needntthey,needntthey,。必须mustnt/neednt,。有必要neednt,5.Youmustnttalklikethat,_?6.Studentsmustnttalkduringlessons,_?7.Marymustbeintheroom,_?8.YoumustlivenearmyfriendifyouliveintheNewStreet,_?9.MikemusthavestudiedFrench,_?10.Theymusthavedonetheirhomeworkyesterday,_?,must/mayyou,mus