情态动词表示推测.ppt

,情态动词表示推测的用法,1.对现在(事情)推测,2.对过去(事情)推测,must+v.(肯定)might/could/may/can+v.(可能)cant+v.(不可能),1.must have done(表肯定性推测)“肯定,准是,”,cant/couldnt have done(表否定性推测)“不可能”,2.may/might have done(表可能性推测)可能,也 许,3.should/ought to have done(表本该做而实际未做的事),shouldnt/oughtnt to have done(表本不该做而实际 已做的事),4.neednt have done(表本不必做而实际己做,造成浪,费,遗憾,不好后果),情态动词表示推测的用法,1.对现在(事情)推测：（情态动词+动词原形）,must+v.(肯定)may/might/could/can+v.(可能)cant+v.(不可能),2.对过去(事情)推测：（情态动词+完成式）,must have done(表肯定性推测)“肯定,准是,”,cant/couldnt have done(表否定性推测)“不可能”,It must have rained last night,for the road is wet.(It cant/couldnt have rained last night.),1.It must have rained last night.for the ditch(水道,渠道)is full of water.,2.-Can it have been a comfortable journey?,3.Ten passangers were in a car!It cant have been a comfortable jurnery.,4.He may have gone to Beijing yesterday.(可能性大)5He might have gone to Beijing yesterday.(可能性小),6.There was plenty of time.She neednt have hurried.7 You should have come to the meeting.,1.-He must be Mr.Li.(肯定是)-No,he cant be Mr.Li.Mr.Li has gone to Britain.(不可能是),2.We may be late for class.Its already seven to five.(也许),3.You mustnt play with fire!,另外,在虚拟语气中还有:would have done 表示“本来会.”但实际上并没有发生,You should have come earlier,otherwise you would have met him.你本该早点来，否则的话，你就会遇见他（实际上没有早来，也没见到他）,must表推测的反意疑问句:反意问句部分永远不带must.1.She must be a teacher,isnt she?2.She must have gone to Shanghai,hasnt she?3.She must have gone to Shanghai yesterday,didnt she?,特殊疑问句疑问词+do you,Thinksuggestbelieveimaginesuppose say,+主语+谓语,(插入语),