情态动词归纳性讲解

PAGEPAGE7情态动词I.种类：1）只能作情态动词:can,must,oughtto,may2)既能情又助：will,shall,would,should3)既情又行为：need,dare4)短语：beableto,haveto,usedto,hadbetter,wouldratherII.用法：1.表猜测，可能性：must,may,might,can,could1)must表肯定“猜测”(指说话人看来一定是，必然是)只能用在肯定句中：Itmustbeheadmaster.Yourfathermustbenearlyfortynow.还可以用mustbedoingHemustbeenjoyinghimself.当must表推测是，否定不用mustnot,而用cannotItcan’tbeheadmaster.表必须，一定：（肯定用must,否定用mustn’t一定不要，表禁止）Youmustn’tsmokehere.2)may,can表可能在肯定句中may表示事实上的可能性，（某事将发生的实际可能性。）can表示逻辑上的可能性：比较：Theroadmaybeblocked.(=Itispossiblethattheroadisblocked.=Perhapstheroadisblocked.)由于某种原因路可能被阻塞了。Theroadcanbeblocked.(=Itispossiblefortheroadtobeblocked.=Itispossibletoblocktheroad.根据逻辑推理表示可能会出现某种情况，并不牵涉具体的事情是否会发生。Accidentscanhappenonsucharainyday.比较：Mr.Lilookspale.Hemaybeill.(事实上的可能性)Mr.Liisinpoorhealth.Hecanbeillatanytime.（逻辑上的可能性）在否定和疑问句中，便不存在这种“事实上的可能性”和“逻辑上的可能性”的区别，因为在否定句和疑问句中，通常是用can而不是用may表示可能。WemaygocampingnextSunday.（事实）Willyouanswerthedoorbell?Itmaybeyourfather.Thismay/might/couldbedonebyhim.Canitbetrue?Whatcanhebethinkingof?3)can,could（一般用于疑问和否定句或感叹句中表惊异，怀疑，不相信的推测）可能，能够Thiscan’tbedonebyhim.Thismaynotbedonebyhim.(弱)Canthisbedonebyhim?Howcanhesorudetoothers?Hecan’tbemorethanthirty.5）情态动词加原形表对一般情况的猜测，但would,could,might并不一定与过去时间有关，而表示可能性弱于它们相应的现在时形式。Hemay/mightbeastudent.Hecan’t/couldn’tbeastudent.6)时态：can,may,mustcan/may/must+do对现在或将来的动作进行推测can/may/must+bedoing是对眼下正在进行的动作进行推测can/may/must+havedone是推测过去时间可能发生的事情must/may/mighthavedone(肯定)can’t/couldn’thavedone(否定)could/can…havedone(疑问)Theymayhavesettledtheproblem.Imighthavecometoawrongconclusion.Theroadisn’twet.Itcan’thaverainedlastnight.CouldMaryhavemissedthefirstbus?Shegotupveryearly.7)反意问句：情态动词表推测，不用情态动词反问，具体根据后面的时态而定：Itmusthaverainedlastnight,didn’tit?Hemusthavetoldyouaboutit,hasn’the?8)should推断的“应该会”不是责任﹑义务的应该WhenwillIgetthisphotos?Theyshouldbereadyby12o’clock.It’s12o’clock.Heshouldcomebackatanymoment.Should=oughtto应该Should/oughttohavedone本应该Should还可译成“竟然”Youcan’timaginethatawell-behavedgentleman___besorudetoalady.A.mightB.needC.shouldD.would【1】You___betiredyou’vebeenworkingforanhour.A.mustnotB.won’tC.can’tD.maynot【2】Excuseme.IsthistherightwaytotheSummerPalace?Sorry,Iamnotsure,.Butit___be.【3】Youmightjustaswelltellthemanufacturerthatmalecustoms___notlikethedesignofthefurniture.A.mustB.shallC.mayD.need【4】Isn’tthatAnn’shusbandoverthere?No,it___behimI’msurehedoesn’twearglasses.A.can’tB.mustn’tC.won’tD.maynot【5】Whoisthegirlstandingoverthere?Well,ifyou___know,hermaneidMabel.A.mayB.canC.mustD.shall【6】2.(表允许)可以may,can,might1)may在陈述句中，may表示“许可”，通常是指说话人给予的许可，口语中可以用can例：Youmay/cansmokeinthisroom.=Youarepermitted(byme)to…Youmay/cancomeifyouwish.否定用maynot表示说话人不许可，例：Youmaynotgo.（=Idon’tpermityouto...）Maynot也可表示一般的不许可，即表示根据一般规定而不是说话人不许可：例：Borrowersmaynottakeoutofthelibrarymorethantwobooksatatime.Can可以用来表示普遍的许可，即不指明是谁给予的许可:Youcankeepthebookformorethantwoweeks.May在疑问句或if从句中,may不是说话人给予的许可，而是征询听话人的许可，例：MayI…征询对方许可比较正式，在口气上比较客气，在口语中用CanI…?May/CanIsmokeinthisroom?(=Willyouallowmeto…)MayIgonow?再问客观上是否允许时用can时更多一些，如：Canwetakethebooksoutoftheroom?2)might,could,would表请求许可时,不表过去，只是语气更加委婉，客气。MightIhavealookatyournewdictionary?--Could/mightIuseyourbiketomorrowmorning?--Yes,youcan/may.No,I’mafraidnot.不能用：Yes,youcould/might.3）shall在疑问句中用于一，三人称表征询听话人的意见或意图，如：ShallIcarryyoursuitcase?(=Doyouwantmetocarryyoursuitcase?Shallwehavedinner?(=Doyouagreetoourhavingdinnernow)WhereshallIwaitforyou?Shallwesithere?Shallhecometoseeyou?要不要他来看你？4）will在疑问句中用于第二人称,表示请求（请对方做某事）would更加委婉WillyouhelpmewithmyEnglish?Willyousingattheconcerttomorrowevening?Wouldyoutellmethewaytothestation?必须用would的场合Wouldyoulike/prefer/lovetogowithme?Would/DoyoumindifIopenthedoor?3.表能力：can和beableto都表能力1)beableto主语必须是人或动物，而can没有这个限制。Hecanswim.=Heisabletoswim.Theradiocanbefixedin30minutes.(不能用beableto)2)beableto可以有任何形式，而can只有过去式couldHewillbeabletoskateaswellasyou.TheforeignerscometoChinawithoutbeingabletospeakChinese.3)beableto的过去式（was/wereableto）可作“设法做成某事讲相当于managetodo或succeedindoingWiththehelpofthefiremen,theywereabletoleavetheburninghouse.(wereableto不能换成could.)4.表必须must,haveto,shallmust说话人的主观意志，或要求某人必须做某事.haveto表客观需要例：Imustgonow,orI’llbelate.shall用于二，三人称表允诺，警告，命令，决心，强制Don’tworry.Youshallgettheanswerthisafternoon.(允诺)Heshallbesorryforitoneday.(警告)Nothingshallstopusfromcoming.(决心)5.will,would1）表意愿（用于陈述句，可用于各种人称,有时态变化）Iwillstopsmoking.Givemyregardstoyourfamily.--Ofcourse,Iwill.Iwishedhimtogiveupsmoking,buthewouldn’tlisten.2）表功能，有时态变化Thedoorwon’topen.Myradiowon’twork.6.表习惯性动作：will,would;usedto“总是”“惯于”Iwillsithereforseveralhours.would/usedtoWhenIwasachild,Iwould/usedtogetupearlyandgofishing.Thereusedtoariverinthevillage.(不能用would)7.回答问句时有变化的情态动词：1)—Mustwehandinourhomeworktoday?Yes,youmust.No,youneedn’t.youdon’thaveto2)MayItakethisbookoutofthereading-room?Yes,youmay.No,youmustn’t.youmaynot.you’dbetternot.3)Needyougonow?Yes,Imust.No,youneedn’t.4)Couldyouexplainittome?Yes,Iwill.(愿意)CouldIuseyourbook?Yes,youcan.(不用could)5)ShallItellhimaboutit?No,youneedn’t.Ihavetoldhim.ShallIinvitehimtogowithus?No,youmustn’t.Idon’twanttoseehimagain.6)Wouldyoumindopeningthedoor?No,indeed.(Ofcoursenot./Certainlynot./Notatall.)若Wouldyoumindmyopeningthedoor?No,goahead.7.need;dareHedoesn’tdare(to)answer.Doeshedaretogo?Don’tyoudare(to)touchit?8.情态动词+havedone1)shouldhavedone本应该oughttohavedoneshouldn’thavedoneYoushouldhavehandedinyourhomeworkontime.Marylookssad.Didyoutellherabouttheaccident.Yes,butIsh