情态动词用法的特征.doc

情态动词用法的特征：1.有一定的词义，但不能单独使用作谓语。2. 适用于主语的各种人称和数 （have to 例外）3. 后面接动词原形，即不带to 的不定式 （have to , used to , ought to 本身带有to )4. 具有助动词的作用， 可用来构成否定句 疑问句及简明答语。 温馨提示：解答情态动词类的题目时，一定要细细领会情景特征，情景中没有任何废话，不要放过任何细节can 和could：1) can的主要用法是：A. 表示能力： eg. The girl can dance very well. B. 表示推测可能性 疑问句和否定句 eg. Can the news be true? You cant be serious.C. _表请求或许可 eg. Can I sit here? Can I leave now?2) could的主要用法是：A. could 是can的过去式, 表示过去 的能力和推测eg. We all knew that the young man couldnt be a doctor.B. could可代替can表示请求, 语气委婉eg. Could I use your bike?1.can /could 表示推测时，只能用在否定句或疑问句中。2. can/could not have done :不可能做某事，表示对过去发生行为进行推测3. can/could have done 本可以，本可能做某事”用于肯定句中，表示对过去发生的事情做出的判断may 和might ：A. may 常用来表示：表示请求、允许; 比can正式:B.表示猜测, 推测 没把握的eg. -I believe the man is from England. But I may be wrong. C. 表示祝愿;语气较正式:eg. May you succeed! 其它用法may well + 动词原形 “完全能，很可能”He may well be proud of his son.他大可因为儿子感到骄傲。may as well + 动原 “最好， 倒不如” You may as well do it at once.你最好马上就做这件事。might 的用法有:A.一般表示过去可能，也可用现在，比may更弱 -Is this Toms bike? - I am not sure, but it might be. B. might + have done 表示对过去发生事情的没把握的判断must 的主要用法：A. _表示必然性。 eg: We must all die. 人总要死的。 B. _表推测，判断，有把握的He always comes first in exams. He must work very hard. Must 表示推测时， 只能用于肯定句。must do 对一般时的肯定推测must be doing 对现在的动作进行肯定推测 must have done 对过去发生的事情作出的肯定判断他们买了一辆新车。 他们一定很有钱They have bought a new car. They must have a lot of money.他现在一定在看小说He must be reading novels now.路是湿的。昨天晚上一定下雨了。The road is wet. It must have rained last night.可能性从大到小: must can could may mightC. _表示强制/义务。 eg: You must get up early. 你必须早起来。注意: must not : “禁止”。 如： - May I take this magazine out? - No, you mustnt. D. _非得，应要- May I smoke here? - If you must , choose a seat in the smoking section.must 答句肯定回答用must , Im afraid so, 或Yes, please.否定回答用 neednt 或者 dont have tomust 的用法1. 必然 2. 推测，判断，很有把握的3. 强制，义务 4. 非得，应要have to 否 dont have to不得不做某事 （客观需要） must 必须（主观需要）I can not see things clearly. I have to wear glasses。We must find a good method to learn computer well. will和would：A. will是助动词或是情态动词 用于构成将来时是助动词。用于表“意志/决心/请求”是情态动词。would亦同理。I will tell you something important. 我将要告诉你一些重要的事Will you tell her that Im here? 请您告诉她说我在这儿，好吗? B. 疑问句中用于第二人称，提出请求 If you want help, let me know, will you? 如果你需要帮助, 让我知道, 好吗?C. _祈使句的反意疑问句常用will 提问 第二人称 Close the door, will/ wont you ? Dont close the door, will you ?3. would比will客气委婉。Would you help us, please? 请您帮助我们，好吗？（表请求）Id go there with you. 我要和你一块到那儿去。（表意愿）Teacher wouldnt allow it. 老师不会允许这件事。（表许可）shall和should：A. shall用于构成将来时是助动词Perhaps I shall pay a visit to England this winter.可能今年冬天我会去英国观光。 B.用于“征求意见”和表 “决心” ,是情态动词用于第一，三人称。Shall we go by train, Mom?（用于征求对方的意见，情态动词）I shall go at once.我必须立即去。（表 “决心”，情态动词）C. shall的主语是第二、三人称的陈述句，表示说话人 的允诺、警告、命令等语气。 will 的主语是第一、二、三人称的陈述句， 表意志、意愿。You shall go with me.He shall be punished.If you will come to my house, I will show you my new painting.should 的用法 :A. 表示“劝告，建议”“责任，义务”去做某事，通常译为“必须，应该。” 表说话人认为主语应该做某事。You should work hard.B_should +have done 表示过去本该做某事，而没做You should have done your homework better.你本该把作业做的更好些。C. Should 表示说话者对于某事难以置信，感到惊讶，译作“竟，竟然”You cant imagine that a well-behaved gentlemanshould be so rude to a lady. Ought to ，should & had betterhadbetter(最好),should(应该)与oughtto（应该）均为提建议、阐述观点的情态动词，其后接动词原形。语气从强到弱 oughtto shouldhadbetter，Every citizen ought to obey law. Young people should learn how to use computersYouhadbettergothereatonce.ought to/should have done表示责备或批评,意为“本应该但”,ought to的语气更强烈,用于否定则表示“本不该但”You should/ought to have told her the truth earlier. She shouldnt have left without saying a word.可兼做行为动词的情态动词：need 、 dare 情态动词 (+动词原形)行为动词need1.无人称和数的变化1.有人称和数的变化2.不受限制3.(sb.) need to do dare to do(sth.) need to be done (sth.) need doing2.不用于肯定句中，用于否定句疑问句中*在if/whether之后;*或与hardly, never, no one, nobody连用;dare3.常以neednt 和darent 的形式出现;4.dare有其过去时dared.1.Need 的否定与答句You neednt return the book now.- Need he start from the beginning? - Yes, he must. - No, he neednt/doesnt have to. 2. neednt have done 表示做了本不必要做的事情,意为“本不必要”Our color TV set is still good enough. You neednt have bought a new one.高考题点击：1. Helen _ go on the trip with us, but she isnt quite sure yet. （05安徽卷）C A. shall B. must C. may D. can说明： shall的主语是第二、三人称的陈述句，表示说话人的允诺、警告、命令等语气；must 加动词原形表示“必须做”；may 加动词原形表示“可能会做”；can 加动词原形表示“能够做”；can 表示“可能性”时一般用在问句和否定句中。该句的关键在于“but she isnt quite sure yet”。 C2. There _ be any difficulty about passing the road test since you have practiced a lot in the driving school. （05上海卷） CA. mustnt B. shantC. shouldnt. neednt说明： shouldnt + 动词原形表示“非常不可能”或“应该不会” ; mustnt 表示“不准”；shant 用在二、三人称中表示“坚决不准”，含有强烈的警告和命令的语气。neednt 表示“不必”；3. Johnny, you _ play with the knife, you _ hurt yourself. (N 1996) B A. wont, cantB. mustnt, may C. shouldnt, mustD. cant, should前句表示“你不能玩刀”，表禁止，所以只能用“mustnt”；后句表示“可能会伤着你自己”，故用 may。4. - When can I come for the photos? I need them tomorrow afternoon. - They _ be ready by 12:00. (N 1998) B A. canB. shouldC. mightD. need此句应是店主对顾客的承诺。5. - Will you stay for lunch? - Sorry, _. My brother is coming to see me. (N 1999) B A. I mustnt B. I cant C. I needntD. I wont此句的关键是 “My brother is coming to see me.” 所以我不能在这儿吃饭。6. - Write to me when you get home. - _. (2001北京春季) C A. I mustB. I shouldC. I willD. I can在回答对方的请求或命令时，应该用 “Yes, I will.”而不能使用 would 或 should。7. I wonder how he _ that to the teacher. (1996上海) D A. dare to say B. dare saying C. not dare say D. dared say注意dare 两种词性的不同用法，做情态动词时候有过去式dared,做行为动词时有人称和数的变化后跟to do.8. When he was there, he _ go to that coffee shop at the corner after work every day. (1996上海) A A. wouldB. shouldC. had betterD. mightwould 在此处表示过去惯常的动作。9.Tom ought not to _ me your secret, but he meant no harm. (N1993) A A. have told B. tell C. be tellingD. having toldought to 相当于 should；此句的关键是“He meant no harm”，显然指的是过去的事。10. I told Sally how to get here, but perhaps I _ for her. (N 1994) C A. had to write it outB. must have written it out C. should have written it outD. ought to write it outshould have written 意指“本该写但实际上并没有写”。11. - There were already 5 people in the car but they managed to take me as well. - It _ a comfortable journey. (N 1995) D A. cant beB. shouldnt be C. mustnt have beenD. couldnt have been此句谈论的是过去的经历，故 A、B 不合题意；must 表示判断和推测只能用在肯定句中。12. - Could I call you by the first name? - Yes, you_. (1998上海) C A. willB. couldC. mayD. might在回答 “Could I ”这类婉客气的