GrammarSuqianSarbrinaWhat’sthedefinitionofmodalverbs?情态动词是一种本身有一定的词义,表示说话人的情绪,态度或语气的动词,但不能单独作谓语,只能和其他动词原形构成谓语。一.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。3)情态动词的“时态”形式并不是时间区别的主要标志,不少情况下,情态动词的现在式形式和过去式形式都可用来表示现在时间、过去时间和将来时间。(1).Weusemodalverbstotalkabout:1.Ability(能力)2.Obligation(义务)3.Certainty(可能性)4.Permission(允许)二.情态动词的语法功能(2).Wealsousemodalverbsto:5.Makerequests(提出请求)6.Makesuggestions(提出建议)7.Makeoffers(提供帮助)8.Giveadvice(提出忠告)情态动词1.cancouldbeableto4.shall2.maymight三.常见情态动词的基本用法5.musthaveto3.willwould7.needdare6.oughttoshould8.情态动词+havedone1.can1)表能力can表能力时意味着凭体力或脑力或技术等可以无甚阻力地去做某事。Icanclimbthispole.Heisonlyfour,buthecanread.Firecan’tdestroygold.①can和could:2)表推测、可能性(用于否定与疑问结构中)Canthenewsbetrue?Itcan’tbetrue.Whatcanhepossiblymean?他可能是什么意思?3)表示请求或允许(和may意思相近)常见于口语。Can(May)Icomein?我能进来吗?CanIsmokehere?我可以在这里抽烟吗?吸烟往往会导致癌症。Smokingcancausecancer.Itcanbeverycoldhereinwinter.这的冬天有时会很冷。4)在肯定句中,can还可表示“有时会,往往会”2)could的主要用法是:A.could是can的过去式,表示与过去有关的能力和推测:eg.Weallknewthattheyoungmancouldn’tbeadoctor.B.could可以代替can表示请求、允许。可表示委婉客气的提出问题或陈述看法Couldyoulendmeyourdictionary?CouldIuseyourbike?Yes,youcan.I’mafraidIcouldn’tgiveyouananswertoday.can/beableto区别:can表示与生俱来的能力或一种客观可能,而beableto更加强调通过后天的学习和努力获得的能力,或者在某个客观的场合和背景下,能做到的事情。Ican’tswim,butIamsureIwillbeabletoswimthroughmorepracticing.Notice:(1).beableto表示能力,有人称和数的变化,可用于各种时态;(2).can表示客观可能性,常指现在,较常用,过去式为“could”;如果只表示能力时,can=beableto(3).could仅表示过去具备某种能力,而was/wereableto表示不仅具备而且实施了某种能力;更侧重于“克服一定困难,经过一定努力做成某事”=managedtodosth.=succeededindoingsth.1.AbigfirebrokeoutinABChotelyesterday.Luckily,everyone__________runoutofthebuilding.wasableto2.She_____speakbothEnglishandFrench.can*Hewasabletoswimacrosstheriverbeforetheshipsank.【Practice】*Hemanagedtogettheradiorepairedwithoutanyhelp.=He______________/________________theradiorepairedwithoutanyhelp.wasabletogetsucceededingettingIcan’tthankyoutoomuch.cannever/can’t……too表示“无论怎样…也不过分”,“越…越好”。你过马路的时候再小心也不为过。Youcan’tbetoocarefulwhilecrossingtheroad.Shecouldn’tbutagreetomyidea.Ican’tthankyouenough.Thefilmcouldn’tbeanyworse.Can或could的否定形式构成习惯短语Can’t...too...Can’t....enough...无论怎样……也不过分……Can’t(help)butdo不得不做,只好做Can’thelpdoing情不自禁Can’thelpit没有办法Can’t...+比较级再……不过了(表示最高级)MayIwatchTVaftersupper?Yes,__________________./No,_______________________.MightIuseyourtelephone?MayIgohomenow?Itmaybetrue.Shemaycometomorrow.Hemighthavesomefever.Mayyousucceed!Mayyouhavemanymoredaysashappyasthisone!youmayYoumustn’t允许,许可禁止,阻止Might比May的语气更委婉表示可能性的推测,译为“大概,可能”用might时显得更加不肯定用于祈使句表示祝愿②.May和MightAcomputer_______thinkforitself;itmustbetoldwhattodo.A.can’tB.couldn’tC.maynotD.mightnotA•may______________can____________表主观“可能”表客观“可能”•cannot___________maynot__________不可能可能不may和can③will和would:will当作情态动词时有以下用法:Ifyougivehimtime,Tomwilltalkandtalkforhours.EverySaturdayeveningtheywillplaychesstogether1.表经常性,习惯性“老是、总是、终归是”2.表示意志,愿望,决心。Iwillgiveupsmoking.---Writetomewhenyougethome.----_____.A.ImustB.IshouldC.IwillD.Ican答案:C我会的主语若为无生命的东西,won't不表示意志,而用来谈论事物的自然属性,表示拒绝,意为“不肯”、就是不……”、或“怎么也不能”。Thewindowwon'topen.=Thewindowrefusestoopen.这窗户打不开。e.g.I’vetriedseveraltimes,butthecarjust______.A.doesn’tstartB.wouldn’tstartC.won’tstartD.didn’tstartCThedoorwon’topen.I’lldomybesttohelpyou.Willyoupleasegivemeamessagewhenyouseehim?---Writetomewhenyougethome.---Iwill.表示功能,译作“能”或“行”意愿2人称,询问对方意愿或向对方提出请求回答祈使句Would当作情态动词时有以下用法:Wouldyouhelpus,please?WhenIhadsometrouble,hewouldencourageme.Wealltriedtostophimsmokinginbedbuthewouldn’tlisten.过去的习惯意愿“要;愿”用于2人称,表示有礼貌的请求或邀请Theoldman_______haveasmokeunderabigtreeeveryafternoonafterhefinishedhisfarmwork.would可表示经常性、习惯性、倾向性。翻译为“经常、惯于、总是”。Would与Usedtodo区别———“过去常常”Would------过去习惯的动作(现在有可能还有此习惯)Usedtodo--------过去习惯的动作及状态(现在已经没有此习惯)④shall:1)用于第一、三人称征求对方的意见,Whatshallhewearonthejourney?Shallwedance?2)shall用于第二、三人称时表允诺,警告,命令,威胁。“必须,应该可以”Ifhepassestheexamination,heshallhaveaholiday.Youshallhaveitbacktomorrow.3)用于第二、三人称用于法律法规条例等文件中的要求。“应该、必须”It’srequiredinourregulationthatstudentsshallgotoschoolontime.Personsunder18shan’tbeemployedinnightwork.(10江苏)—Ihaven’tgotthereferencebookyet,butI’llhaveatestonthesubjectnextmonth.—Don’tworry.You______haveitbyFriday.A.couldB.shallC.mustD.may解析:shall在第二人称中表示允诺,还可以表示强制,命令,威胁,警告。还有在法律条文中的要求或规定。答案:BYoubepunishedforwhatyou'vedone.你一定会因为你的所作所受到惩罚。shallhecleantheblackboardforyou?Takeiteasy.You_________beofferedajobinthiscompany.Mike___________sparenoefforttostudy.(1)“Theinterest______bedividedintofivepartsaccordingtotheagreementmadebybothsides.”declaredthejudge.A.mayB.shouldC.mustD.shallshallshallD表“法律法规等文件中表示义务或规定”(2)---Excuseme,butIwanttouseyourcomputertotypeareport.---You_______havemycomputerifyoudon’ttakecareofit.A.shan’tB.mightnotC.needn’tD.shouldn’t(3)Thebosssaidtothesecretary,“Ifyouworkwell,you______havearise.”A.mustB.oughtC.shallD.wouldAC表“警告”表“允诺”2.should表示义务、建议、劝告等,意为“应该”。(oughtto)Studentsshouldrespectteachers.Theboysshouldn’tbeplayingfootball;theyshouldbeatschool.It’s4:30,TheyshouldbeinNewYorkbynow.劝告、建议义务、责任常规、常理的推测(正常情况下)按理应该Heoughttosucceed,asheissod