初中英语情态动词讲解

1情态动词（一）情态动词的定义:情态动词表示说话人对某一动作或状态的态度。（二）情态动词的特点1.情态动词有一定的词义。2.情态动词不能单独做谓语，它必须和其他动词的原形一起构成谓语。3.情态动词没有人称，数的变化。（三）情态动词的结构和意义1.情态动词的基本句型肯定句：主语+情态动词+动词原形+......否定句：主语+情态动词+not+动词原形+......疑问句：情态动词+主语+动词原形+......2.情态动词的意义must“必须”；can/could“能，会”；may/might“可以”；should“应该”；would“愿，要”；haveto“不得不”；need“需要”（四）情态动词的基本用法1.can(could主要指过去时间)1）表示人或物本身所具有的能力，意为“能，能够，会”:Twoeyescanseemorethanone./Icanswimverywell.2）表示可能（理论上或是逻辑判断上）Hecan’t(couldn’t)haveenoughmoneyforanewcar.3）表示允许：CanIhavealookatyournewpen?Heaskedwhetherhecouldtakethebookoutofthereading-room.4）表示对现在动作或状态的猜测，主要用于否定句和疑问句中或感叹句中:Hecan’t(couldn’t)beoversixty.他不可能超过六十岁。5）could表示比can更委婉客气的提出问题或陈述看法，指的是现在时间。Can(Could)youlendmeahand?帮我一把好吗？2.may(might)1）表允许，询问或说明一件事可不可以做，might指过去时间；但在疑问句中might也可指现在时间，语气比may更委婉。May(Might)Iaskforaphotoofyourbaby?我可以要一张你宝宝的照片吗？在回答以may引起的问句时，肯定回答是一般可仍用may,或Yes,please./Certainly./Sure./Ofcourse.；否定回答根据说话人的语气由强到弱分别选用:mustnot(mustn’t)（禁止）/hadbetternot（最好别）/maynot（不行）2)may表可能,但所表示的可能性不如can所表示的那样肯定。might可以指过去时间，也可以指现在时间，但语气更加不肯定。Hemaybeathome.他可能在家。Theymightbehavingameeting,butI’mnotsure.他们有可能在开会，不过我不肯定。3.must（haveto表示客观需要）1）表示“必须”（主观看法）时，用于肯定句或疑问句；用于否定句时表示“禁止”。Wemustdoeverythingstepbystep.我们一切都必须循序渐进地做。Youmustgethomebefore9:00.2）表示揣测。意为“想必、准是、一定”等，只用于肯定句。Hemustbeill.Helookssopale.他准是病了。他的脸色苍白。3)must的疑问句，肯定回答用must，否定回答用needn’t或don’thaveto。4.should1）表责任或义务，意为“应该”，用于各种人称。2Youshouldbepolitetoyourteachers.你对老师应该有礼貌。2）表推测，意为“想必一定、照说应该、估计”等。Thefilmshouldbeverygoodasitisstarringfirst-classactors.这部新电影是一流演员主演的，估计拍得很好。5.will1）表意愿,用于各种人称。Iwilldoanythingforyou.我愿为你做任何事。2)will在疑问句中用于第二人称，表示询问对方的意愿或向对方提出请求Willyouclosethewindow?请你把窗户关上好吗？6.would1）will的过去式，表示过去时间的“意志、意愿”。Theywouldnotlethiminbecausehewaspoorlydressed.他们不让他进去因为他衣着破旧。IsaidIwoulddoanythingforyou.我说过我愿意为你做任何事。2）would用于现在时间，表示比较委婉地提出请求、建议或看法。Wouldyoulikeanotherglassofbeer?再来杯啤酒好吗？7.need1)need作为情态动词，主要用于否定句疑问句；作为实义动词可用于肯定句，否定句或疑问句中。Youneedn’ttelephonehimnow.你现在不必打电话给他。2)回答由need引起的问句时，肯定回答一般用must，否定回答是用needn’t--NeedIcome?--Yes,youmust.--我需要来吗？--需要。情态动词练习题(一)单项选择1.__________Itakeitout?I'msorry,you__________.A.Could...couldn'tB.Might...mightnotC.Could...canD.May...can2.Needwedothisjobnow?Yes,__________.A.youneedB.youshouldC.youmustD.youcan3.__________tohavelunchwithustoday?A.DoyoulikesB.WouldyoulikeC.WillyoulikedD.Haveyouliked4.-IsJohncomingbytrain?--Heshould,buthe__________not.Helikesdrivinghiscar.A.mustB.canC.needD.may5.Peter__________comewithustonight,butheisn'tverysureyet.A.mustB.canC.mayD.will6.Ithoughtyou__________behungry,soIhavebroughtyousomecakes.A.mayB.mightC.canD.could7.Comeon!We__________hurrybecausethereisn'tmuchtimeleft.A.mayB.mustC.canD.need8.AmydidbestintheEnglishtest.She__________hardlastweek.A.mustworkingB.shouldhaveworkedC.shouldworkD.mustwork9.—Wouldyouliketodrinksomejuice?—Thanks._________,butIhavedrunkalotiftea.A.I’dlovetoB.IthinksoC.I’mafraidnotD.Idon’tthinkso.10.—MayIsmokehere?—No,you______!Look,thereisa“NOSMOKING”signhere.A.mayB.maynotC.needn’tD.mustn’t11.—Listen!Helenissinginginthenextroom.—It_____beHelen.ShehasgonetoBeijing.A.can’tB.mustn’tC.mayD.should12.—Whatdodriversdowhenthetrafficlightsturnred?—They______stopandwaittillthegreenlight.A.mustB.canC.mayD.need(二)根据语境用适当的情态动词填空：31.“________Ileaveschoolnow?”“No,you_______cleantheclassroom.”2.It’stimeforclass.You________stopplalyingfootball,oryou_______belateforschool.3.“_______theyanswerthequeationinRussion?”“No,they________.”4.—________Ihandinmypapernow.—No,you_______.Butyou________handitintomorrow.5.“________youskate?”“No,I________.Butmybrother_________”6.We_________crossthestreetcarefully.7.Heisveryclever.He_________knowtheanswer.