情态动词详细用法归纳.doc
-!情态动词详细用法归纳 情态动词有具体的词义,但也同助动词一样,需要与其他词语一起构成句子的谓语,另外情态动词没有人称和数的变化,情态动词后必须跟动词原形。考点一:can,may,must 等情态动词在陈述句中的用法:1. can 的用法:(1)表示能力、许可、可能性。 表示能力时一般译为“能、会”, 即有种能力,尤其是生来具备的能力。如:She can swim fast, but I cant . 她能游得很快,但我不能。could是can的过去式。表示过去的能力。 be able to do sth. 常常指经过努力,花费了时间和劳力之后才能做到某事。(2) 表示许可,常在口语中。 如:You can use my dictionary. 你可以用我的字典。(3) 表示推测,可能性,意为“可能”, 常用于否定句和疑问句中, 此时cant 译为“ 不可能”。 如:Can the news be true? 这个消息会是真的吗?Can it be our teacher?那个人有可能是我们老师吗?No, it cant be our teacher. He is on a visit to the Great Wall.不可能。咱们老师正在游览长城呢。【例题】I think Miss Gao must be in the library. She said she would go there. No. She be there, I have just been there. A.cant B.mustnt C.neednt D.wouldnt【解析】根据下文“我刚去过那儿”可知,应为“ 不可能”, cant 表示推测答案 A2. could的用法:(1)can的过去式,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。(2) 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 give me a hand? 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。(用could问,不能用could答。)3. may的用法:(1)表示请求、许可,比can 正式。如:May I borrow your bike? 我可以借你的自行车吗?You may go home now. 现在你可以回家了。【例题】_ I borrow your MP3? Sure . Here you are. A. May B.Should C.Must D. Would【解析】 在此处表示请求,意为“ 做可以吗”。答案:A (2) 表示推测,谈论可能性,意为“ 可能, 或许”,一般用于肯定句中。may not 翻译为“可能不” 。 如:It may rain tomorrow . 明天可能会下雨。 She may be at home. 她可能在家呢. (3) may的过去式为might ,表示推测时。可能性低于may。 如:He is away from school. He might be sick.他离开学校了,可能是他生病了。 (4) 表示希望、祈求、祝愿,常可译为“祝愿”。通常是用may +主+V 例如:May you have a good time. 祝你过得愉快。 May you be happy! 祝你幸福! May you succeed!祝你成功!4. must的用法:(1)must 表示主观看法,意为“必须、一定”。 如:You must stay here until I come back.在我回来之前你必须呆在这儿。 (must引导的疑问句) Must I finish my homework right now? 我必须现在交作业吗? 肯定回答:yes ,you must. 否定回答:No, you neednt/ dont have to(2) 其否定形式mustnt表示“ 一定不要 ” “千万别” “禁止, 不许”。如:You mustnt play with fire. 你不许玩火。 You mustnt be late. 你一定不要迟到。(3) must表示有把握的推测,用于肯定句,指百分百肯定。 如: The light is on, so he must be at home now.灯亮着,他现在肯定在家。(4)must 和have to 都有”必须”的含义,但侧重点不同: must强调说话者主观(自己)的看法。 have to强调客观(外力作用)的需要,也可以翻译为“不得不”。例如:I must go to school and learn some Knowledge.我必须会学校上课学一些知识。(自己要回) I have to go to school because the holiday is over.假期结束了我不得不回学校上课了。must 没有人称和数的变化,而have to 有动词单三形式:has to 和 动词过去式:had to 将来时:will have tomust not=mustnt 表示禁止.当must提问时,肯定回答用must。否定回答用neednt 和dont have to5. need的用法:(1)need做情态动词时: 表示“需要、必须”,主要用于否定句和疑问句中,其否定形式为neednt,意为“没有必要,不必”。 用need 提问时,肯定回答为 must,否定回答为 neednt或dont have to。 如:Need I do my homework now? Yes, you must .是的。 No. you neednt /dont have to. 不, 你不必。(2)need 还可以作实义动词,此时有人称、数和时态的变化,如果主语是人sb.: sb. need(s) sth. 某人需要某物sb. need to do sth. 某人需要去做某事need的单三needs. 过去式needed。 变否定借助dont/doesnt /didnt 如:I need to pass the exam. 我需要通过这次考试。He needs to learn English .他需要学习英语。如果主语是物sth.: Sth. need doing 某事需要被做 = need to be done这种情况下应注意两点:.主动形式的动名词doing具有被动的含义;.该动名词可以改为其动词不定式的被动形式而句子的意义不变。例如:. Your car needs washing. = Your car needs to be washed. 你的车需要洗了。6. shall 的用法:shall表示征求对方意见(多用于第一、三人称),如:Shall we go out for a walk? 我们出去散步好吗?在英语中,我们可以用其他多种方式提出我们的建议或征求对方意见。shall意为”要不要.? “好吗?”用于第一人称,表将来,而will可用于任何人称。(1) 用“Lets do.”来提出建议。如:Lets go for a walk after supper.(2) 用“What/How about.?”来提出建议;about后接名词或动词ing形式。如:What about/How about a drink? What about/How about taking Tom with us?(3) 用“Why not.?”来提出建议,表示“何不”not面后接动词原形。“Why not.?”实际上是“Why dont you/we.?”的简略形式。如:Why not meet at the school gate at eight? Why dont we stay here another day?(4)用“Would you like.?”来提出建议,意思是“你想要吗?”Would you like后可接名词或不定式。如:Would you like a cup of tea?Would you like to go and see her?因此,如果我们说:“去游泳好吗?”英语中可有这样几种表达法:Shall we go for a swim?Lets go for a swim,shall we?What about/How about going swimming?Why not go for a swim?Would you like to go for a swim?What do you think of going for a swim?6. should的用法:(1)should 意为“应该” ,可表示劝告、建议、义务、责任等。 如:We should protect ourselves. 我们应该我们自己。should not=shouldnt +do动词原形had better 的用法:had better 意为“最好”,没有人称的变化,后接+动词原形,其否定形式为:had better not。如:We had better go home now. 我们最好现在回家。 You had better not go home now.你最好现在不要回家。should和had better 可以互换should not=shouldnt和had better not可以互换7. will 的用法:表示意愿、意志、打算,可用于多种人称。如:I will help you if Im free this afternoon.今天下午如果我有空,我就会帮你。是一般将来时的“标志词”,will+ do动词原形考点二:含有情态动词的疑问句的回答:1. 对 may 引出的问句,可以有下列回答方式:Yes,you may. Yes, of course.Yes, certainly.Sure .No, you mustnt. No, you cant.2.对must引出的疑问句,回答方式为:Yes, must. No, neednt/ dont have to.3.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?Yes, you can.可以。(回答不用could)4. shall引出的疑问句用于第一人称, 表示征求对方意见或客气的请求。其回答方式有以下几种:Yes, please.All right.No, thank you.5. would you的回答方式有以下几种:Yes, I will. (No, I wont.)Sure . (Im sorry , I cant.)All right/ OK/ With pleasure.Certainly. (No, thank you .)Yes, please.6. will you ?提问回答方式,可以使yes,./no也可以。Id be glad to.【例题】Would you give me a hand and pass my thanks to Lily? _.A.Thats right B.With pleasure C.It doesnt matter D.No trouble【解析】A. 意为“对了” ,B.意为“ 乐意效劳”, C. 意为“ 没关系” D.意为“不费事”。答案:B考点三:不同情态动词的否定意义也不同:1. (1)cant可译为“不会”。 如:I cant play basketball. 我不会打篮球。(2) 当句子表推测时,用cant 表达”不可能”; 如:He cant be ill. He is playing chess with Tom. 他不可能病了,他正和Tom 下棋呢。(3) cant 还可用来回答“ May I ? ” 这样的问句; 如:May I come in ? 我可以进来吗?No, you mustnt. / cant. 不,你不能。(4) cant 还可用于固定习语中。cant help doing 禁不住,情不自禁 cant wait to do sth 迫不及待如:She cant help crying. 她不禁大哭起来。The children cant wait to open the box. 孩子们迫不及待地想打开盒子。2. may的否定式为 may not,译成“ 可能不”。如:He may not be at home. 他也许不在家。3. (1)mustnt 表示不许,不可。如:He mustnt leave his room. 他不许离开他的房间。You mustnt talk in class. 你们不可以在课上说话。(2) mustnt 也可用于以 may 表示要求时的否定回答中。如:May I stand here? 我可以站在这里吗? No, you mustnt (cant). 不,不行。4. neednt 意为“ 不必”。如:You neednt meet him unless youd like to.你不需要见他,除非你愿意。5. shouldnt 表示不应该。如:You shouldnt feel so unhappy over such little things. 对于这种小事,你不应该感到这么不高兴。考点四: 情态动词表示推测的用法:一、“情态动词+动词原形”表示对现在的推测。1、must表示肯定的推测100%的肯定,一般用于肯定句中。如:He must be at home because the light is still on.2、Should表示推测的可能性比较大,must的可能性 小一点。如:It is already 10 oclock now they should be there.3、can表示推测时一般用于否定句或疑问句。如:Who is knocking at the door?Can it be the postman?could表示推测时,语气can比要弱,说话者留有余地 如: Could it be an animal? It could not be, because it is not moving.4、may 表示推测,用于肯定句。might也可以表推测 只是表示其可能性较小于may。如:The man may be your new teacher.Where is Mr Li? He might be working in his office.情态动词(实战演练)( )1. John_ come to see us tonight, but he isnt very sure yet. A. may B. can C. has to D. must( )2. They _ do well in the exam. A. can be able to B. be able to C. can able to D. are able to( )3. He_ be in the classroom, I think. No, he _ be in the classroom. I saw him go home a minute ago.A. can; may not B. must; may not C. may; cant D. may; mustnt( )4. Shall I get one more cake for you, Dad? Thanks, but you_, Ive had enough. A. may not B. must not C. cant D. neednt( )5. Even the top students in our class cant work out this problem, so it _ be very difficult. A. may B. must C. can D. need( )6. You _ be late for school again next time. A. mustnt B. neednt C. dont have to D. dont need to( )7. You_ ask that man over there. Maybe he knows the way.A. had better not to B. had not better C. had better D. had better not( )8.Shall we go and visit the History Museum next Sunday? _.A. Here you are B. Sorry , I cant C. Yes, please D. Let me try( )9Why dont you ask Mike to go with us? Thanks, _. A. I will B. I wont C. lean D. I may( )10. _ I take the newspaper away? No, you mustnt. You_read it only here.A. Must; can B. May; can C. Need; must D. Must; must( )11.You_ worry about your son. He will get well soon. A. neednt B. cant C. mustnt D. have to( )12.The poor man needs our help, _ he? A. need B. neednt C. does D. doesnt参考答案1-5. A D C D B 6-10. A C B A B 11-12. A D