情态动词必修unit1

GrammarModalverbs情态动词(I)Unit1Festivalsaroundtheworld·情态动词的语法特征1）情态动词不能单独做谓语，除ought和have外，后面只能接不带to的不定式。2）情态动词没有人称，数的变化，但有些情态动词，如can、will也有一般式和过去式的变化。can,could和beableto的用法Shecan/beabletosingthesonginEnglish.Thismachinecanmakeyoufeelcomfortable.1.can,beableto都可表示“能力”Can的主语是人或物,beableto的主语是人We’llbeabletofinishtheworksoon.Ihaven’tbeenabletoseethefilm.2.can只用于现在式和过去式(could)。beableto可以用于各种时态。could用于表示泛指过去的能力。如：IcouldreadwhenIwasfour.Althoughthesoldierwasbadlywounded,hewasabletotellwhathadhappened.Sheranfastbutshecouldn’t/wasn’tabletocatchthebus.3.表示特定的某一过去能力或表示成功地做了某事时，只能用was/wereableto，不能用could。HewasabletofleeEuropebeforethewarbrokeout.Hewasabletoswimhalfwaybeforehegottired.表示过去的能力CouldIhavealookatyournotebook?Yes,youcan./No,youcan't.4.could不表示时态,表示委婉的请求，（注意在回答中不可用could）。Canthisnewsbetrue?Howcanyoubesofoolish?Itcan’tbeMary.Shehasfallenill.5.表示“惊异,怀疑,不相信”的态度(主要用于否定句,疑问句和感叹句中)Lindadidn’tcatchthetrain.Shecouldhavecaughtit.(时间→过去）Don'tworry.Theycouldhavejustforgottentophone.(时间→过去）6.表示推测，译为“可能、或许”，can常用于否定句(意思是不可能做了)和疑问句；could除用于否定句及疑问句外,还可用于肯定句(意思是本来可以)。IsawMrWangjustnow.Hecouldn'thavegonetoBeijing.(时间→过去）must和haveto1.Must用于一般问句中,肯定回答用must否定式用needn’t或don’thaveto，做“不必”,mustn’t表示“禁止，不允许”—MustIfinishallassignmentsatatime?—Yes,youmust.No,youneedn't.Youmustn’tgetdownwhilethecarisstillmoving.Idon’tlikethisTVset.Wemustbuyanewone.Therewasnomorebus.Theyhadtowalkhome.2.表示“必须”这个意思时，must和haveto稍有区别。must着重说明主观看法，haveto强调客观需要。另外，haveto能用于更多时态。Youmustbethenewteacher.Hemustbejoking.Thereisnobodyhere.Theymusthaveallgonehome.3.must表示对某人某事的猜测，作“准是”，“一定”，一般用于肯定句中。对过去发生的事情作肯定判断用musthavedoneMustyoumakesomuchnoise?4.Must表示“偏要，硬要”，指做令人不快的事情shall,should和oughttoYoushalldoasIsay.(命令)Tellhimthatheshallhavethebooktomorrow.(允诺)Nothingshallstopmedoingit.(决心)1.shall用于第二、三人称表示允诺、警告、命令、决心等。ShallIopenthewindowforyou？（征求意见）Shallhefetchsomewaterforyou？（请求）2.在疑问句中,用于第一、三人称，用来表示请求或征求意见。Youngpeopleshouldlearnhowtousecomputers.Everycitizenoughttoobeylaw.Yououghtnottogo.3.should常表示劝告、建议、命令，与oughtto意义相近，但oughtto多表示责任、义务，语气强烈。在疑问句中通常用should代替oughtto。Youshould/oughttohavetoldherthetruthearlier.(时间→过去）Sheshouldn’thaveleftwithoutsayingaword.(时间→过去）4.should/oughttohavedone表示责备或批评,意为“本应该做到…但没有做到…”,用于否定则表示“本不该…但”oughtto的语气更强烈.Idon'tknowwhyyoushouldthinkthatIdidit.—whereisBettylivingnow?—HowshouldIknow?5.Why(orHow)+should表示说话人对某事不能理解，感到意外、惊异等意思。意为“竟会”。may和might---MayIuseyourpencil?---Yes,youmay./No,youmustn’t.1.may和might用于一般问句中表示委婉的请求,肯定回答用may,否定用mustn’tShemaynotbeworkingnow.Johnmightbeathomenow.2.may和might表示“可能性”,may/might+v指现在或将来可能发生的动作情况。might暗示的可能性更小Shemay/mighthavegonetothecinema.Theymay/mightnothavereceivedourtelephone.3.对过去发生的事情的可能性作出判断用may/mighthavedone,用might比用may的可能性更小Mayyousucceed!MayGodblessyou!4.may放在句首祈使句，表示祝愿。Will和wouldIfyouwillhelpmewithmyEnglish,Iwillbeveryhappy.IpromisedthatIwoulddomybest.1.will和would表示意愿、意志，可用于各种人称Willyoutellhimthenewsassoonashecomesback？Wouldyoupleasespeakagainmoreslowly？2.在疑问句中,will用于第二人称,表示请求或征求意见,would则语气更委婉1.---Therewerealreadyfivepeopleinthecarbuttheymanagedtotakemeaswell.---It____acomfortablejourney.()A.can'tbeB.mustn'thavebeenC.shouldn'tbeD.couldn'thavebeenD2.Peter___comewithustonight,butheisn’tverysure.A.mustB.canC.mayD.willC3.Withsomuchworkonhand,you____toseethegamelastnight.A.mustn’tgoB.couldhavegoneC.shouldn’tgoD.shouldn’thavegoneD4.Johnny,you______playwiththeknife,you____hurtyourself.()A.won't;can'tB.mustn't;mayC.shouldn't;mustD.can't;wouldn'tB5.Imissedthebus,soI___gohomeonfoot.A.mustB.mayC.canD.hadtoD完成句子1.I____________________themovie----it’llgivemehorribledreams.(watch)我本不应该去看那部电影的-----它会使我做噩梦的。2.Theelectricity_____________________lastnight,fortheworkerswereexaminingtheelectricwire.(cut)昨晚，电肯定切断了，因为当时工人们正在检修线路。3.I________________________thatbitterperiodwithoutyourgeneroushelp.(go)没有你慷慨的帮助，我不能熬过那段痛苦的日子。4.Oh,mygoodness!Mylaptop______________________.Iputithereonethedesk,butnowit'snowheretobefound.(steal)哦，天哪！我的笔记本电脑肯定被偷了。我把它放在桌子上了，现在哪里都找不到了。shouldn’thavewatchedmusthavebeencutoffcouldn’thavegonethoughmusthavebeenstolen