情态动词一,定义:表说话人对某一动作或状态的情感或态度。二,用法:不单独使用,与动原连用,无人称,数的变化。基本用法推测判断,虚拟三,基本用法:1,cancould(1)表能力Shecanliftherhusbandwithonehand.分类用法:Womencanholduphalfthesky.注:如表示过去某人有能力做而且做成某事,要用was/wereabletodo=succeedin=managedtodocould过去有能力,但做了与否不知道。Thefirespreadthroughthehotelquickly,buteveryone___getout.AwasabletoBcould(2)表示为委婉请求,这时could不表示过去,而是语气更好。---Can/CouldIleavehome?---Yes,youcan.Can表许可(3)Howcanyouleavehome?用在否定、疑问句中表示惊讶、怀疑、猜测或不相信。Canthewomenbehiswife?Ifwintercomes,canspringbefaraway?(4)理论客观上的可能性Everyonecanbenumberone.Anelephantcanfitintoafridge.Sheisbad-tempered,butshecanbesweetandgentlesometimes.2,maymight(1)表请求或许可---MayIleavehome?---Yes,youmay.注:表请求许可,may正式有礼,口语中可用can/could代替。疑问句中表请求许可may/might/can/could代替。给予许可只用may/can.---Can/Could/MayIwatchHappyCampaftersupper?---Yes,youcan/could/may.(2)表现实可能性,用may.Damaomaybeamillionaireoneday.(3)表祝愿只用mayMay+主语+动原Mayyousucceed!MayGodbewithyou!Mayyoutwobehappy.Mayhappinessandhealthfollowyou!(以上例句可用还原法。)3must,haveto(1)必须,一定。其否定及其强烈,表示不准,绝不可以。Youmustn’tspeakillofothers.回答must问句,肯定用must;否定needn’t/don’thaveto.Thereisonethingintheworldthatyouneedn’t/don’thavetocommunicate./uselanguage.(love)---MustIwashthedishesatonce?---Yes,youmust.(2)表示一个人固执,一定要,偏偏MustyouseethefilmIfyouaretheone?Whymustyousingsongsatsuchalatehour?---Whoisthatgirl?---Ifyoumustknow,sheisDragon,myfriend.(3)must表示主观看法,无人称变化,只有现在式;haveto表客观要求,不得不做,有人称和时态变化。4will,would(1)用于第二人称疑问句,询问对方意愿,向对方提出请求,这时would不是will的过去式,而是语气更委婉。Willyouhavesomemilkytea?(2)表主语的意愿决心,自愿做某事。翻译成“愿意,会”---willyougoshoppingwithme?---Iwill.(3)Will表示现在经常性的动作行为。would表示过去经常性的动作行为。WhenIwasyoungI’dlistentotheradio,waitingfor…5,shallshouldshall(1)用于一,三人称疑问句,表征求意见或请求对方指示Shallwegooutforlunch?Shallhecomeorwaitoutside?Whenshallxiaomaoleavehospital?(2)用于二、三人称陈述句表命令、警告、威胁、决定或允诺。Everyoneshallwearschooluniform.Youshallpayforit.Should(1)情感形容词或分词之后的从句中表竟然I’msurprisedthatheshouldhavebeencheatedbysuchasimpletrick.(2)同why,how连用表强烈的感情---Givemesomemoney.---WhyshouldI?Oughtto+动原(客观)=should(主观)疑问句ought在句首否定句oughtn’ttoYououghttoseethefilmRedCliff.6.Need(无过去式)dare(dared)(1)作为情态动词,可用于疑问否定和条件句,不用在肯定句Youneedn’tcaretoomuchaboutwhatotherssay.Hedarenotgooutatnight.Howdareyoucomparemetomilkytea.(2)用作实义动词有时态,人称和数的变化。Needtodo肯定句daretodo否定句,疑问句to可省略。•四,情态动词的推测判断、虚拟用法•1,情态V.+动原•(1)must表推测,译为“一定,必须”只用于肯定句,较有把握,后有根据•XiaoshenyangmustbefromLiaoningProvince.•Youmustbetiredofgrammer.•(2)can表推测判断时只用于否定句,译为“不可能”和“可能……?”•Themooncan’talwaysbefull.•Wherecan/couldXiaoshenyangbefrom?•(3)could表推测判断时译为“可能,也许”可用于各种句式(肯,否,疑问)表不太肯定而不是过去时。•XiaoshenyangcouldbefromLN.•Themooncouldn’talwaysbefull.•(4)maymight•表推测判断时译为“可能也许”只用于肯、否定句,此时might不是过去式,而是可能性更小。•注意:表推测判断时•1must的否定为can’t/couldn’t;疑问式为can/could,而不是mustn’t•2can’t/couldn’t意为:不可能•may/mightnot意为:可能不•3在肯定句中共有三个词表可能,也许•couldmaymight•(5)shouldoughtto•表推测判断时,译为“应当,应该”,是按常理,常识或一般情况进行推测,具有很大的可能性,说话人具有很大的把握,但语气比must弱。•---WhencanIcomeforthephotos?•---They____bereadyat12:00.(should/must/may/might)•2.情态V.+havedone•(1)musthavedone表示过去一定发生过某事,其后常有根据或一定已经完成了某事,只用于肯定句。•Hemusthavebeenmadyesterday.•YoumusthaveheardofXiaoshenyang’sEnglishname.•(2)canhavedone只用于否定,疑问句,分别表示“过去不可能”和“过去可能……”•Themooncan’thavebeenfulllastnight.•Canhehaveheardofhisname?•(3)couldhavedone可用于各种句式•在否定、疑问句中相当于canhavedone•在肯定句中两种含义:•a.过去可能做过某事或可能完成了某事;•b.过去本能够做但未能做,有时含有委婉的批评或责备(虚拟)。•Hecouldhavemarriedanygirlhewantedto.•Youcouldhavebeenkindtothedog.•注意:musthavedone的否定,疑问为•can’t/couldn’thavedone•can/could...havedone...?•(4)may(not)havedone只用于肯定、否定句中•过去可能做过或已完成某事。•YoumaynothaveheardofXiaoshenyang.•Mr.Liumaynothavebeenmad.•(5)might(not)havedone用于肯定、否定句•在否定句相当于maynothavedone•在肯定句中:a.过去可能做过或已完成某事,相当于mayhavedone•b.过去本来可以做但未做,有时含有委婉的批评或责备(虚拟)。•Hemighthavemarriedanygirlhewantedto.•Youmighthavebeenkindtothedog.•注意:表过去可能做过某事或可能完成了某事有三种表达:•could/may/mighthavedone;•表过去本来可以但未做,有时含有委婉的批评或责备(虚拟)。•could/mighthavedone•(6)should(not)havedone过去本应该做而没做;本不应该做而做了•含责备,埋怨,不满等语气。还可用ought(not)tohavedone•Youshould/oughttohavebeenkindtoyourneighbor’sdog.•Youshouldn’t/oughtn’ttohavetakenhergirlfriendaway.•(7)needn’thavedone/didn’tneedtodo•过去本没必要做但做了•Weneedn’thavelearnedsomuchgrammar.•Wedidn’tneed_____________________.•Heneedn’thavecaredsomuchaboutmoneybecausemoneycouldn’tbuyhimlove.tolearnsomuchgrammar•(8)情态动词表推测判断时,后跟的V.形式常有4种•a)+V.原,对现在或将来的推测判断•Youmustbetiredofgrammar.•Youmustbeproudofyourselfinfuture.•b),+bedoing,对现在进行或将来推测•Shecan’tbelearninggrammarthistimetomorrow.•c),+havedone对过去或已发生事情的推测判断。•d),+havebeendoing对过去某个时刻正在发生的事情的推测判断;或表过去某个时间一直持续不停地延续到过去某个时间或现在的事情的推测。•以上要点重在理解。•(9)情态动词表推测判断的反义疑问句不再使用情态V.而是根据不同情况选用不同系V.或助V.•Itshouldbenicetobeacat,isn’tit?•Youmusthaveheardofhimbytheendoflastnight,hadn’tyou?•Itmusthaverainedlastnight,didn’tit?•Youmustbetiredofgrammar,aren’tyou?•Hecan’tbelearninggrammar,ishe?•注意:此类题目可先去掉原句中的情V.,把原句变成另一个时态、动词意义相对应的句子,再选用不同的系/助动词。•(10)情V.+havedone的反意疑问句有两种•a,如句中有确切表过去的时间状语,把此句看成一般过去时,用一般过去时的助动词did/was/were•b,如句中无表过去的时间状语,把此句看成现在完成时,用现在完成时的助动词have/has•Youmusthaveheardofhim,haven’tyou?•Thecruelwifemusthavebeenkilled,hasn’tshe?•Youmusthaveheardofhimlastyear,didn’tyou?•Thecruelwifemusthavebeenkilledlastnight,wasn