情态动词用法大全

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,Grammar:,Modal verbs,情态动词,情态动词有,can,may,must,ought(to),will shall,dare,need,八个。在众多的英语动词中，情态动词有其独特的用法，概述如下：,1.,其中五个有过去形式，分别是：,cancould,情态动词的过去形式往往表示的是一种语气，而不是时态。（,dared,属例外，只表示时态。）,maymight,willwould,shallshould,daredared,e.g.,Can/Could I help you?(,后者更加委婉,),He may/might come today.,（后者表不肯定）,Will/Would you please do it again?(,后者更加委婉,),You shall/should do it all by yourself.(,前者语气极为严厉，后者则只是一种规劝,),情态动词的过去形式往往表示的是一种语气，而不是时态。（,dared,属例外，只表示时态。）,2.,情态动词不能单独使用，在句子中往往与不加,to,的不定式一起构成谓语,e.g.,We must/can/may/will/shall face any difficulty,ought,后面须跟加,to,的不定式,e.g.You ought to go out for a rest.,3.,情态动词,will,shall,还可用作助动词，用于将来时,e.g.,We shall/will go home next weekend,He will come here again when he is free.,Cf.,If you will come,he will meet you,If you come,he will meet you.,上述两句均为复合句，后半句都是将来时，上句中的,will,表示“愿意”为情态动词，不表示将来。下句中的,if you come,则是不用助动词的将来时态。,4.,情态动词,dare,need,通常只用于否定或疑问,e.g.,Who dare do it?,You neednt go now.,试看下列的填空：,Well try to finish the work in time,but we need_ some more workers,A.ask for B.to ask for,选项,A,为不加,to,的不定式，那么此时的,need,为情态动词，此句为肯定句显然不适，答案为,B need to do,中的,need,为行为动词,5.dare,need,还可用作行为动词，后面可跟加,to,的不定式,试比较，,A.who dare do it?B.He dares to do it.,A.He neednt do it B.he needs to do it,上述句子中,A,句为含情态动词的句子，,B,句中,dare.need,均为行为动词,注意动词,dare,的某些特殊用法。,1,）在下列句子中只可用情态动词,dare,，不可用行为动词,dare,How dare you say I am unfair?,I dare say,.(*I dare to say,X),e.g.,Dont worry,sir.I dare say,nobody will come again,.,2),行为动词,dare,后面跟不定式时，在下述三种情况之一时可省去不定式符号,to,与助动词连用时（即用于否定，疑问句）,e.g.,He doesnt dare(to)go to the forest done at night.,Do you dare(to)touch the tiger in the case?,与,never,连用时,e.g.,The man never dares(to)do anything without his owners permission.,当,dare,出现在,WH(,连接代词,),引导的名词从句中时,e.g.,They wonder why the little boy dares(to)live in such a dangerous place.,6.,情态动词不能用作不定式,(,不与助动词连用,),试看下列填空,Tomorrow Ill_ go home to see my parents.,must B.have to,(,B,为正确答案，助动词,will,后是省略,to,的不定式,),7,.,情态动词的否定式可直接加,not,来表示,will notwont,shall notshant,must notmustnt,dare not darent,need notneednt,may not maynt (“,或许不”“可能不”,),（“不可以要用”,cant,mustnt,）,can notcant-cannot,can+not,并非都可以写成,cant,cannot,e.g.,He cannot speak Chinese.,He can not only speak Chinese but English.,上述两句中第一句可译成“他不会讲英语”（此时可用,cant,）,第二句可译成“他可以不讲英语,”,结论：,当,not,否定,can,时，可写成,cant(cannot),，,当,not,否定后面的不定式时，则不能用,cant,上述第二句中,not onlybut(also).,则表示“不仅。而且。”此时,not,与,can,无关，显然不能用,cant,。,8,情态动词的疑问式可通过情态动词前移的方式来表示,e.g.,-Can/(Must/May/Shall/Will/Dare)he do the dangerous work?,Ought he to do the work alone?,(1),肯定作答，通常用原情态动词,e.g.,-Can/(Must/May/Shall/Will/Dare)Mr.Li stay in the lovely house?,-Yes,he can(must/may/),若是情态动词,need,引出的问句，则要用,must,作答,e.g.,-Need I write an article now?,-yes,you _(A.must B.need),答案只能是,A.,（,2,）否定回答，通常用原情态动词的不定式,e.g.,-Can he go now,-No,he cant.,若是情态动词,may,，否定回答用,mustnt,或,cant,。若是,must,则用,neednt,作答,若是,need,可用,neednt,或,do not have to,e.g.,-May I go out for a walk?-No you_.,may not B.must not C.cant D.dont,答案为,B,或,C,-Must we do it now?-No,you _,A.dont B.mustnt C.cant D.neednt,答案为,D,-Need I do the work again?,-No,you_,A.neednt B.dont C.mustnt D.cant,答案为,A,9.,情态动词用法分述,will,I.,表现在经常发生的情况,e.g.,The man will go to work every day.(=The man goes to work every day,后者更常用,),The door wont open.(=The door isnt easy to open.),II.,表示“决心”“意愿”“可能”等,e.g.,Hes full of faith and he will beat all his matches.,If you will come tonight,hell meet you,I think.,This will be the book you are looking for.,Will you come in?(=Will you please come in?),III.,若表示过去，则用,would,e.g.,He would take a walk after supper when he lived in the country.,He said he would help.,表示“过去常常,”,除了用,would,，还可以用,used to,，不过后者常常含有“现在不,”,之意。,e.g.,When young,he would go out for a trip on Sundays.(Now maybe still does),When young,he used to go out for a trip.(But now he doesnt),此外，,would,表示“过去常常,”,时后面动词须是某种行为或动作，不能是静态动词。,e.g.,Near the village,there _ be a stream.,A.would B.used to(,答案是,B),Would,更多的用来表示语气而不是时态,e.g.,Would/Will you please take a seat?,Would/Will you mind opening the windows?,I would/will do anything for you,sir.,有时甚至只能用,would,而不用,will,e.g.,I would like.Would you like.?,They would love.He would rather,2)shall,I.,表示“询问”用于一、三人称,e.g.,Shall I open the door?,要我开门吗？,Shall he stay here for the night?,让他留下过夜吗？,II.,表示允诺，用于二、三人称,e.g.,If you/they work well,you/they shall be well paid,III.,表示“强制”“威吓”等，用于二、三人称,e.g.,He says he wont come,but I say he shall.,If you go there again,you shall lose what youve got.,Should,是,shall,的过去式，它本身的词义为“应当”（,ought to,）,Shall,的上述三种用法中，,I,、,II,两种不可用,should,，否则句意变了。,在,III,中若用,should,则语势较弱。,Should,在虚拟语气中的用法这里暂不介绍,3)may,I.,用于肯定句,表示“可能”,“,允许”,II.,用于否定句,表示“或许不”,III.,用于问句,表示“请求许可”或”惊讶”,e.g.,You may do it.,It may be a new house.,Mr.Li may not be in his office.,How old may she be?,She looks so young while her husband loods so old.,May I make a suggestion?,Might,是,may,的过去式,但用于现在时中则表示更不确定,e.g.,She might stay at home now.,Might I take this seat?,4)must,表示“必须”“一定”等,eg,You must come next week.,He must be in trouble.,must,与,have to,的用法,前者侧重于主观意念,后者则用于表示客观条件或义务,译为”只好”“不