情态动词can的基本用法.doc

情态动词can的基本用法：情态动词can有一定的词义,但不能独立存在,它必须与动词原形一起构成谓语。情态动词can没有人称和数的变化。其具体用法如下:1.表示"能、会",指脑力或体力方面的"能力"。例如:I can speak English.我会讲英语。Jim can swim but I cant.吉姆会游泳,但我不会。2.表示"可能",常用于否定句或疑问句中,指某种可能性，此时cant译为“不可能”。例如:Han Mei cant be in the classroom.韩梅不可能在教室里。Can he come here today, please?请问他今天能到这里来吗?3.表示"可以",常用于口语中,指许可或请求做某事，可以代替may。例如:Can I have a cup of tea, please?请问我可以喝一杯茶吗?You can go out.你可以出去了。补充：can的过去式could，意为“能、会”，表示过去的能力如：He could write poems when he was 10.他十岁时就会写诗。could在疑问句中，表示委婉的语气，此时could没有过去式的意思。如:Could you do me a favour?你能帮我个忙吗？Could I use your pen?我能用一下你的钢笔吗?Yes, you can.可以。（注意回答）情态动词can的基本句型：1.肯定句型为:主语+can+动词原形+其它。例如:They can play basketball.他们能打篮球。She can dance.她会跳舞。You can go to watch TV.你可以去看电视了。2.否定句型为:主语+can not(cant/cannot)+动词原形+其它。表示"某人不能(不会。不可能)做"。其中cant是can not的缩略式,英国多写成cannot。例如:You cannot pass the ball like this.你不能像这样传球。I cant ride a motorbike.我不会骑摩托车。3.疑问句句型分为:一般疑问句句型和特殊疑问句句型两种类型。一般疑问句句型为:Can+主语+动词原形+其它。表示"某人会(能。可以)做吗?",用于口语时,常表示请求或许可。其肯定答语用""Yes,主语+can."作答;否定答语用"No,主语+cant."作答。注意答语中做主语的人称代词,应根据问句中的主语作相应的变化。其变化规则为:第一人称问,则第二人称答;第二人称问,则第一人称答;第三人称问,第三人称答。例如:-Can you sing an English song for us?你可以为我们大家唱一首英语歌吗?-Yes.行。(注意在Yes后面常省略I can)-Can I skate?我可以滑冰吗?-Yes, you can.可以。-Can she climb hills?她能爬山吗?-No, she cant.不,她不能。特殊疑问句句型为:a. Who+can+动词原形+其它。该句型中who相当于主语。例如:-Who can sing in English in your class?你们班上谁会用英语唱歌?-Lily can. 莉莉会。b.特殊疑问词(作定语)+名词+can+主语+动词原形+其它。该句型中的特殊疑问词常用how many, how much等。例如:-How many boats can you see in the river?你能看见河中有多少只船吗?-Only one boat.仅有一只。c.特殊疑问词+can+主语+动词原形+其它。该句型中的特殊疑问词常用what, where, when等,一般用肯定陈述句作答。例如:-What can you see in the picture?你能在图画中看到什么?-I can see some birds and two big trees in it.我能看到一些鸟儿和两棵大树。考查can的用法：a. 考查can表示能力的用法。在这一用法中，can表示能力，意思是"能，会"，其否定式cant表示"不能"。在过去时中用could和couldnt。例如：1. - Wheres Mr. Lee? I have something unusual to tell him.- You _ find him. A. may not B. may not C. cant D. cant2. - Finish drawing a horse in ten minutes. OK?- Sorry. It _ in such a short time. A. may do B. cant be done C. must do D. neednt be done3. I have my own room in my house, so I _ do what I want in it. A. must B. have to C. need to D. can4._you mend my car? I _ not start it. A. Would; would B. Must; must C. Can; can D. May; may5._she ride when she was three years old? A. Can B. Could C. Need D. May6. The boy _ answer this kind of hard questions one year ago. A. can B. may C. couldb. 考查can表示推测的用法。在这一用法中，can意为"可能"，表示客观可能性，常常用于疑问句和否定句中。例如：7. - Who is the man over there? Is it Mr. Li?- No, it _ be him. Mr. Li is much taller. A. mustnt B. may not C. cant D. neednt8. - Listen! Someone is singing in the next room. Who _ it be? Is it Wei Fang?- No. It _ be her. She is at school now. A. will; may not B. must; mustnt C. may; cant D. may; wont9. - Is Mr. Hu in the reading room?- No, he _ be there. He has gone to Tianjin. A. mustnt B. neednt C. wont D. cant10. Class 3 won the football match! _it be true? A. May B. Must C. Will D. Canc. 考查can / could表示请求许可的用法在这一用法中，can和could都表示现在，用could比用can语气更加委婉客气，常用Could I / you.?句式，表示"我/你能吗?"，若表示同意要用can，不用could。例如：11. - Could I look at your pictures?- Yes, of course you_. A. could B. can C. will D. might12._you pass me a pen? Id like to write down the telephone number.A. Need B. Could C. Must D. Should 综合练习：1. -Can I go fishing with you, Dad?-No, you _.You _stay at home and do your homework first.A. wont; may B. cant must C. shouldnt; ought D. neednt; should2. -Do you know whose dictionary it is?-It _ be Li Meis. Her name isnt on it.A. cant B. mustnt C. shouldnt D. neednt3. -I cant stop smoking, doctor.-For your health, Im afraid you _.A. can B. cant C. must D. mustnt4. -Is Mr. Brown driving here?-Im not sure. He _ come by train.A. may B. shall C. need D. must5. _ your friend play basketball?No, he _.A. Cans; cant B. Can; doesnt C. Does can; doesnt can D. Can; cant