高中英语2024届高考复习情态动词知识讲解

高考英语情态动词知识讲解一、认识情态动词情态动词是一种助动词，本身有一定的词义，协助主要动词表达说话者的情感态度。情态动词不能单独作谓语，必须和动词原形构成谓语。情态动词没有人称和数的变化。二、常见的情态动词can，could；may，might；must；shall，should；will，would；need；dare；ought to；have to；used to；had better/best；would/had rather三、情态动词的基本用法1、can&could（1）表“能力”现在“能”用can，过去“能”用could（2）表“可能/以”提建议、请求、命令；否定形式表“不可以/允许”Can you hold on a minute，please？You can't stay here.（3）有时会It can be too hot here，especially in summer.（4）can't/couldn't...better/worse/more pleased“极其好/差/高兴”以及can't/couldn't...enough等---How are you doing？---Fine！Couldn't be better.2、may&might（1）肯定句中表示允许，疑问句中表请求，意为“可以”---May I take a swim？---Yes，you may.---No，you mustn't/may not./mayn't.Might I have a cup of tea？You may go.Pets may not be taken into the carriages.You might sit by my side.（2）may/might表猜测，意为“可能，也许”表示对过去情况推测时，多用于肯定句He may not be at home now.You might have forgotten about it.It may not be true.这可能不是真的。比较：It can't be true.这不可能是真的。（3）表祝愿May there never be another world war！但愿再也没有世界大战。May you enjoy yourself every day！祝您每天过得开心！（4）may/might as well do...；may well do...前者表示“不妨，倒不如”；后者表示“很可能”If that is the case，we may as well stay at home.What you say may well be true.3、must（1）必须主观用must；客观用have to；过去必须做某事，用had to；对must的否定回答，可用needn't或doesn't/don't have toMan must have oxygen in order to live.When I was your age，I had to get up early every morning.---Must I work tomorrow？---No，you needn't/don't have to.（2）否定句中表“不许，禁止”之意You must not go there on your own.We must never forget our heroes.（3）肯定推测，表“一定”之意Did I say that？I must have been out of my mind.The light is still on.He must be at home.（4）表“偏要，硬要”之意，用于条件句和疑问句Must you make her cry？你非得把她弄哭？Why must it rain on Sunday？为什么偏要在星期天下雨？Please smoke outside if you must smoke.如果你硬要抽要，请到外面抽。4、shall和will二者既可用作助动词，表示将来时，又可用作情态动词。（1）一、三人称的疑问句中，表示征求对方意见。Shall I open the door？我要不要开门？Shall he/she/they go there？他/她/他们要不要去那里？（2）二、三人称的陈述句中，表示许诺、威胁、命令、警告、决心、规定等。表许诺的例句：You shall hear everything about it.你可以听到有关此事的一切。You shall have whatever you want.你想要什么就有什么。表示威胁的例句：She shall not stay under my roof！她不可以呆在我的屋子里！You shan't go to the party if you don't do as I tell you.如果你不按我说的去做，你就不可以去参加聚会。You shall suffer for this！你会为此吃苦头！表示命令的例句：---Shall she come tomorrow？---Yes，she shall.---她明天要来吗？---是的，她明天必须来。表示规定的例句：Each competitor shall wear a number.每个参赛者都要戴上号码。Those belonging to our club shall wear uniforms.我们俱乐部的那些成员必须穿制服。（3）will用于第二人称单数疑问句表请求Will you tell him I'm here？请你告诉他我在这里好吗？If you want help，let me know，will you？如果你需要帮助，通知我好吗？（4）will用于各种人称表示习惯和倾向，意为“”总是会，总要要，老要，老是”She will sit for hours，waiting for her son to come home.她总要坐几个小时，等着儿子的归来。People will talk.人们老是说三道四。Women will be women.女人终归是女人。（5）否定的will用于各种人称，表示“不肯、不愿、不会”，表示不具备某种性能，相当于refuse toOil and water won't mix.油和水不相溶。The door won't open.门打不开。Matches won't strike if they are damp.火柴潮湿就是擦不着。5、should和ought toshould和ought to都可以表示“应该/当”，它们的否定形式分别为should not（shouldn't）和ought not（oughtn't ）to（1）在某些从句中，作为虚拟语气的一种表达，一般都可以省略It's necessary that he should come to the office.她有必要到办公室来一趟。The coach required that the gymnasts should practise at least 5 five hours per day.教练要求体操运动员们每天至少训练5小时。（2）表示惊讶、不以为然、忧虑、惋惜等情绪，表“竟然”之意It's a pity that you should be so careless.真遗憾你居然这么粗心。Why should you talk to me like that？你竟然这么和我说话？It's really unfair that this should happen to us.我们竟然发生这样的事，真是不公平。It isn't right that such near neighbours should not know one another.这么近的邻居竟然彼此不认识，这不正常。It's simply a miracle that rice should grow in such a place.稻子竟然能在这样的地方生长，这实在是个奇迹。（3）在对将来的虚拟条件句中，可用if...should do...，should不可省略，省略if，需要使用部分倒装结构If it should rain，what would you do？=Should it rain，what would you do？万一下雨，你会怎么办？（4）should/ought to have done和should not/ought not to have done前者表示“本该做实际上并未做”，后者表示“本不应该做而实际上做了”，常表示埋怨、责备或悔恨You should/ought to have known the truth.你本该知道真相。You should not/ought not to have known the truth.你本不应该知道真相。6、would和used to（1）would第二人称的疑问句，表示请求，比will更委婉Would you knidly show me the way to the station？劳驾，请问到车站的路怎么走？You would like some tea，wouldn't you？您要喝茶，是吗？Which would you rather do，go to the cinema or stay at home？你愿意去看电影还是待在家里？Would you mind changing places with me so that I can be nearer to the fire？你能不能与我换一换位置，这样我可以离炉火近一点？（2）would可用于虚拟条件句中If I were you，I wouldn't agree.我要是你，我不会同意。He would have been killed if the car had gone over the cliff.如果汽车当时翻到悬崖下，他早就丧命了。（3）would可表示过去习惯性动作或倾向He would come to help us when he was free.以前他有空会来帮我们忙。Occasionally he would come to see me in the past.他过去有时会来看望我。（4）wouldn't表示过去某物体不具备某种性能The door wouldn't open，no matter how hard she pushed.无论她怎么推，们就是打不开。The woud wouldn't heal.伤口不能愈合。（5）used to不能与具体的过去时间连用，接be动词时，表示过去的习惯，不用would，而只能用used to beHe used to be lazy.他过去很懒。7、need&dare它们既可以用作实义动词，又可以用作情态动词。（1）need用作实义动词，意为“需要”，后接名词或to do...，否定形式为don't/doesn't/didn't need等。He needed all his charm to persuade her that it wasn't his fault.他需要使出浑身解数来让她相信那不是他的错。Do you need to go so soon？你需要这么快就走？She doesn't need your help.她不需要你的帮助。（2）need用作情态动词时，用于否定词与疑问句---Must I come？---Yes，you must.---No，you needn't（don't need/have to）.（3）needn't have done表示“”本没必要做......”You needn't have mentioned it.你本没必要提这件事。（4）dare用作实义动词，后接to do...；有时，dare后的to可省略The girl didn't dare to go home.Who dares to go there alone？I have never dared disturb him.She didn't dare show her face.I have never dared disturb him.（5）dare用作情态动词，主要用于疑问句，否定句和条件句，表示“敢”She dared not even look at me.How dared he do such  things？8、had better&would/had ratherhad better（not）do...最好（不）做...；would/had rather （not）do...宁可（不）做...You'd better go before the storm comes.Which would/had you rather do，go to the cinema or stay at home？He would/had rather die than surrender.