情态动词及情态动词的被动语态

情态动词有哪些?can/may/must/will/shall/should/oughttoneed/darehadbetter/wouldrather,usedto/ haveto/beableto第一页1第二页，共14页。情态动词的含义序号原形过去式主要含义1cancould2maymight3mustmusthadto4needneeded5daredared6willwould7shallshould1.能力2.请求/准许3.可能性1.请求/准许2.可能性*3.祝愿1.义务(必须);2.猜测(肯定)需要敢愿意1.征求意见2“应该”(should)第二页2第三页，共14页。序号原形过去式主要用法8beabletowas/wereableto9havetohadto10oughttooughtto11usedto12hadbetter13wouldrather“能够”（能力）“不得不/必须”“应该”“过去（常常）”“最好”“宁愿”情态动词的含义第三页3第四页，共14页。

can/couldbedone

mustbedone

shouldbedone

may/mightbedonehadbetterbedone

havetobedone含情态动词的被动语态：情态动词+be+PP第四页第五页，共14页。否定式：情态动词+not+be+p.p

can/couldnotbedone

mustnotbedone

shouldnotbedone

may/mightnotbedonehadbetternotbedone

havenottobedone第五页第六页，共14页。疑问式：情态动词+主语+be+p.p

can/could+主语+bedone

must

+主语+bedone

should+主语+bedone

may/might

+主语+bedonehad+主语+betterbedone

have+主语+tobedone第六页第七页，共14页。1.Icanfinishthework.Theworkcanbefinishedbyme.Cantheworkbefinishedbyyou?2.We

shouldplantmanymoretrees.Manymoretreesshouldbeplantedbyus.

Shouldmanymoretreesbeplantedbyus?第七页第八页，共14页。Teenagers

shouldbe

allowedbyparentstodrivethecar.3.Parentsshouldallowteenagerstodrivethecar.Shouldteenagers

be

allowedbyparentstodrivethecar?4.Youcanpasstheexam

ifyoustudyhard.Theexamcanbepassed(byyou)ifyoustudyhard.Cantheexambepassed(byyou)ifyoustudyhard?第八页第九页，共14页。water(浇水)Treesmustbewatered

bythemeveryday.Theymustwatertreeseveryday.Musttreesbewatered

bythemeveryday?第九页第十页，共14页。Peoplemaycatchfishintheriver.Fishmaybecaughtintheriver(bypeople).Practice:第十页第十一页，共14页。1.Mymother

cancookdeliciousmeals.

Deliciousmealscanbecookedbymymother.2.Students

willuse

thesetextbooksnextterm.Thesetextbooks

willbeusednexttermbystudents.3.Youshouldwatertreesoften.Treesshouldbewateredbyyouoften.4.Youmustnotplanttreesinverydryearth.Treesmustnotbeplantedbyyouinverydryearth.第十一页第十二页，共14页。3.Sixteen-year-oldsshouldbeallowedtodrive.(先改为否定句，再改一般疑问句)

Shouldsixteen-year-oldsbeallowedtodrive?Sixteen-year-oldsshouldn’tbeallowedtodrive.Yestheyshould./No,theyshouldn’t