情态动词用法+have-done.ppt

《情态动词用法+have-done.ppt》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、ModalVerbsLet’sLearncancouldbeabletomaymightmustshallshouldwillwouldoughttodareneedhavetousedtohadbetter常用的情态动词：情态动词＋havedonecan/could/may/mighthavedone(1)都表示对过去所发生的事情的推测。意为“也许／可能已经”。肯定句:may/might/couldhavedone(≠canhavedone)否定句:can’t/couldn’t/maynot/mightnothavedone疑问句:Can/Could/Might

2、…havedone?(≠May…havedone?)—She’stwohourslate—whatcan/couldhavehappened?Can/Couldhehavemissedhertrain?—Yes,shemay/mighthave.Shemay/might/couldhaveoversleptandgotuptoolate.MightIhavelostitsomewhere?Compare:Hecan’t/couldn’t/maynot/mightnothavegoneoutbecausethelight’son.(现在对过去的推测)Ithought

3、hecouldn’t/mightnothavegoneoutbecausethelightwason.(过去对过去之前的推测)Ithoughtitmightrain.(Itmayrain.)Iaskedifitcouldrain.(Canitrain?)(过去对过去将来的推测)Mywife’sinhospital—ourbabycould/may/mightarriveatanytime.(现在对将来的推测)—Whatdoyouthinkthatnoisewas?—Itmay/might/couldhavebeenacat.(现在对过去的推测)—Whatdoyou

4、thinkthatnoiseis?—Itmay/might/couldbeacat.(≠can)(现在对现在的推测)(2)could/mighthavedone还表示过去本能够／本可以做某事是而实际没有做，有时含有“责备”之意。Inmyview,theaccidentcould/mighthavebeenprevented.Youcould/mighthavetoldmeaboutitearlier.(3)could/mighthavedone还表示过去本会发生某事而幸好没有发生。Youwerestupidtotryclimbingupthere.Youcould

5、/mighthavekilledyourself.Youshouldn’thaverunacrosstheroadwithoutlookinground.Youmight/couldhavebeenknockeddownbyacar.(4)could/mighthavedone还用于虚拟语气中。表示“过去本会做某事”而没有做。Ifhehadnotbeenbusythen,hecould/might(也可用would)havehelpedme.=Hecould/might/wouldhavehelpedme,buthewasbusythen.=Hewasbusyth

6、en.Otherwise/Or/Orelsehecould/might/wouldhavehelpedme.Hecould/might/wouldhavehelpedme,evenifhewasbusy.Icould/might/wouldnothavefinisheditintimewithoutyourhelp.2.musthavedone表示对过去所发生的事情的肯定推测,意为“肯定／一定做了或发生了某事”。只用于肯定句中。Someonemusthaveopenedthecage—thelioncouldn’thaveescapedonitsown.Ididn

7、’thearthephone.Imusthavebeenasleep.Compare:—Wasthatthemanagerwhowalkedby?—Itmusthavebeen./No,itcan’thavebeen.—Isthatthepostmanwhoisknockingatthedoor?—Itmustbe./Itcan’tbe.3.should/oughttohavedone表示过去本应该做某事而实际上没有做，含有“责备”之意。Theplant’sdead.MaybeIshouldhavegivenitmorewater.IknowIoughtnotto

8、havet