情态动词表示说话人的某种感情或语气，对某一动作或状态的某种态度。表示“需要、可以、必须、应当”等。什么是情态动词？(modalverbs)Note2Note1functionsofModalverbsabilitycertaintypermissionobligationmakerequestsmakesuggestionsmakeoffersgiveadvice能力义务确定许可提出要求给出建议提供帮助提出忠告LiuXiangcanrunthe110mhurdleracewithin13seconds.can/could:can/could:1.can一般表示与生俱来的能力或者一种客观可能性,还可以表示请求和允许。He_____driveacar.canMancannotlivewithoutair._______Iuseyourbike?Cancan/could:2.在疑问句中，用could可表示请求，语气较委婉。—____Ihavethetelevisionon?—Yes,you_____./No,you_____Couldcan/maycan’t/I’mafraidnotcan/could:3.表示惊异、怀疑、不相信的态度。（主要用在否定句、疑问句或惊叹句中）He’ssuchanicepersonthathe______committhecrime.can’t你怎么会如此地粗心！Howcanyoubesocareless!Thiscan'tbetrue?can/could:4.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.can/beableto区别:Edisonalwayswonderedwhyhenscouldhatch(孵)chickenswhilehewasnotableto.Question:Arethetwomodalverbsinterchangeable(互换)?Ifnot,why?can表示与生俱来的能力或一种理论上的客观可能，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。can/beableto区别:1.AbigfirebrokeoutinABChotelyesterday.Luckily,everyone__________runoutofthebuilding.wasableto2.She_____speakbothEnglishandFrench.canMayIeatKFCifIwinthegoldmedal?may/might:may/might:1.表示许可。表示请求、允许时，might比may的语气更委婉一些。—Might/MayIuseyourcomputer?—Yes,youcan./No,youcan’t/maynot/mustn’t.may/might:2.用于祈使句中表示祝愿。3.表示推测、可能(只用于肯定句)可能性比较小。祝你成功！Mayyousucceed.Hemaybeverybusynow.Mayyoubehappyallyourlife.ShiDongpengmightwinamedalattheOlympicGames.Althoughthechanceofwinningamedalissmall,I’lltrymybest!may/might:must1.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/don’thaveto.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。I’msotired!Ihavetodothetrainingforatleast10hoursaday!…yethemustworkhardtowinthegoldmedal.AlthoughLiuXiangissogiftedinhurdlerace…mustYoumustbethenewteacher.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musthavedone—Howoldareyou,madam?—Ifyoumustknow,I'mtwicemyson'sage.4.must表示“偏要，硬要”，指做令人不快的事情1.—They___bedoingtheexperimentinthelab.—Why？—Becausethelightsarestillburning.A.couldB.canC.mustD.wouldA.couldB.canC.mustD.would2.Ifyou___smoke,pleasegooutside表示肯定的推测表示偏要，硬要advisability（可劝性）必要性necessityoughtto/shouldhavetomustYourmotherbringsyouupandtakesgoodcareofyou,sowhensheisold,you___lookafterherinreturn.A.canB.mayC.havetoD.mustveryuncertainalmostcertainmightshouldmustmaycouldoughttowill1.He_____beathome.2.He_____beathome,forhejustcalledmefromhishome15secondsago.A.mayB.mightC.mustA.mayB.mightC.must(can)shall1.Shall用于第一、第三人称疑问句中，表示说话人征求对方的意见、向对方请示或提供帮助。Whenshallhebeallowedtoleavehospital?Shallwedothetraininginthemorning...
