情态动词can,may,must的用法.

情态动词㈠can的用法may的用法must的用法王家春can的用法1.Icanliftthestone.2.Youcanborrowmybiketomorrow.3.Canitbetrue?4.Itcan’tbetrue.㈠.1.能力2.许可3.猜测（用于疑问句、否定句）㈡.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。㈢.常用句型1.couldhavedone2.can/could…havedone?3.can’t/couldn’thavedone1.Shecouldhaveexplainedthematter.2.Canshehavetoldalie?3.Wherecan/couldhehavegone?4.Hecan’t/couldn’thavesaidthat.5.Shecan’t/couldn’thavebeenathomeallthistime.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./I’mafraidyoucan’t.4.Imayborrowthisbook,mayn’tI?㈠。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.Hecan’tknowthetruth.Hemaynotknowthetruth.他不可能知道真相。他可能不知道真相。㈡。mayhavedone可能做过1.shemayhavemissedthebus.2.Itmayhavedrizzledduringthenight.must的用法1.Youmustgetupmuchearlier.2.Youmustnotspeakillofothers.3.Mustwewashthedishesatonce/Yes,youmust.No,youneedn’t./youdon’thaveto.4.Ourboymustdotheoppositetowhatweordered.5JustwhenIwasbusy,shemustcomeandchatter.6.It’s10o’clock.Mymothermustbeangry.7.Wethoughtourteachermustbejoking.㈠。1.必须、一定2.偏偏3.猜测（用于肯定句）㈡。musthavedone肯定做过1.Itmusthaverainedlastnight.Thegroundiswet.2.Nooneanswersthephonebell.Theymusthavegoneout.㈢。构成的反意疑问句1.Wemustworkhardatmaths,____________?2.Youmustrealizethatwecan’tallowsuchbehavior,_____________?3.Theymusttothereatonce,_________________?4.Thehousesmustbecleanifthereareguests,_________？neednt’twemustn’tyouneedn’ttheyneedn’tthey⑴。必须—mustn’t/needn’t⑵。有必要—needn’t5.Youmustn’ttalklikethat,_____________?6.Studentsmustn’ttalkduringlessons,______________?7.Marymustbeintheroom,___________?8.YoumustlivenearmyfriendifyouliveintheNewStreet,____________?9.MikemusthavestudiedFrench,___________?10.Theymusthavedonetheirhomeworkyesterday,____________?must/mayyoumust/maytheyisn’tshedon’tyouhasn’thedidn’tthey⑶。mustn’t禁止、不许—may/must⑷。猜测—与must后的动词一致⑸。有过去时间的短语或从句时—didn’t