1、高中英语必修三情态动词（ unit 1 ，unit 2）一、情态动词的特点:1.没有人称和数的变化。2. 有些情态动词有过去式的变化:e.g. will would , can could , may might , dare dared二、情态动词的否定式: 情态动词+ not +动词原形can not: cant , must not: mustnt , need not : neednt三、情态动词的用法及相互区别, 是考试的内容之一1. can , be able to be able to 表示经过努力后, 能够做到; be able to 有多种形式的变化。can 1). 表示体力
2、或脑力方面的能力; 2). 表示允许、可能性。could 是can的过去式, 表示过去有能力及过去存在的可能性 ; 用于疑问句表示委婉地提出问题。1) The fire spread through the hotel very quickly but everyone _ get out. (NMET 97 )A. had toB. wouldC. couldD. was able to 2) -Will you stay for lunch? -Sorry, _. My brother is coming to see me. (NMET99)A. I mustntB. I cantC.
3、I needntD. I wont 2.may 表示询问或说明一件事可不可做; 表示某事有可能发生。might是may的过去式; 用在疑问中比may委婉、客气。1) -May I take this book out of the reading-room?-No, you mustnt. ( Yes, you may.)2) -Might I make a suggestion? -Yes, you may.3. must 1). 表示必须要做的事: 必须 2) 表示很有把握的推断: 一定, 准是。have (has)to : have (has)got to 必须, 不得不。过去式: ha
4、d to3) -Must I get to the station before three oclock?-Yes, you must. ( No, you neednt. )4) Im afraid you will have to wait a while.5) She must be in the classroom now.6) Mary _ be in Paris, I saw her in town only a few minutes ago. (NMET 94)A. mustnt B. shouldnt C. cant D. may not4. shall 1) 在疑问句中,
5、 用于第一、三人称表示说话人征求对方的意见或向对方请求。2) 用于二、三人称,表示说话人给对方的 命令、警告、允诺等概念。1) - Shall I place an order with you now? -No, you neednt. -Shall he turn down the radio a bit? -Yes, please.(No, please dont.)2) You shall have the English book as soon as I finish it.3) Everything that he owns shall be taken away from hi
6、m.4) Your brother seldom comes to see you, _?A. does heB. doesnt heC. will heD. isnt he5) Its a fine day. Lets go fishing, _?A. wont we B. will we C. dont we D. shall we5. should 应该 ; 应当1) You should listen to the doctors advice.2) You should study the article carefully.6. will, would1) 在疑问句中用于第二人称,
7、表示说话人向对方提出请求或询问。用would语气更加婉转。2) will 表示现在的习惯性动作或状态; would 表示过去的习惯性动作或状态。3) will 用于各种人称, 表示 意志、意愿、决心、允诺; would 表示过去时间的 意志、意愿、.。(1) Dont smoke in the meeting room, _ you? A. do youB. will youC. can youD. could you-Will you come with me? -Yes, I will.(I am sorry , I cant.)(2) -Would you tell us somethi
8、ng about yourself? -Yes, I will.(3) - Its my birthday tomorrow. Dont forget to come to my party.- _ .A. I dont B. I wont C. I cant D. I haven7. ought to 应该; 应当1) You oughtnt to smoke too much.2) She _ for what she has done.A. ought to praiseB. ought be praisedC. ought to have praisedD. ought to be p
9、raise8. dare 1. dare to come 2. dare come1) He dare not tell the truth. 2) He doesnt dare to come out at night.3) I dont know whether he _ try.A. dareB. needsC. wantsD. is allowed9. need 1). 作为情态动词:必须 2). 作为实义动词: 需要A.主语是人 need( to do something ; to be done by somebody) B. 主语是事物 need ( doing; to be d
10、one) 1) -Do they need to take any books with them?-No, they dont need to.2) -Need we buy any new equipment? -No, we neednt.3) This farm tool needs repairing. This farm tool needs to be repaired. 4) -Shall I tell John about it ?- No, you _ . Ive told him already.A. neednt B. wouldnt C. mustnt D. shou
11、ldnt5) Its a fine day. You _ take a raincoat with you. A. cant B. mustnt C. neednt D. may not情态动词 + 不定式的完成式是高考的考试要点1、must have done,“一定做过/一定已经”，表示对过去情况极大把握地推测，仅用于肯定句2、may/might have done 也许做过某事（推测）；本来可以做某事却没做3、cant have done 为否定句或疑问句,对过去的推测“不可能，一定没做过某事” could have done本来可以做某事却没做4. neednt have done 表
12、示”不必要做某事，但做了”，而neednt do 则表示”不必做(也没做)”5.、ought to /should have done 表示”本来应当做的却没做” oughtnt / shouldnt have done 本来不应该做某事却做了6、would/could/might/should + have done 用来表示与过去事实相反的虚拟语气7、would rather have done 表示”当时宁愿做了某事”，否定形式：would rather not have donee.g. If I had been free that day, I would have gone with you.8、would like/love to have done 表示” 本想做某事” 而实际上未做。
