1、Unit 2 Sports events,Modal verbs,Grammar and usage,情态动词,一、特征 1) 情态动词本身有词义, 表示说话人的语气或情态,但词义不完全, 不能单独作谓语动词, 只能和不带to的动词不定式 (ought等除外)。即动词原型一起构成谓语动词。 2) 情态动词所表示的情态有: 命令、允许、请求、拒绝、愿望、愿意、义务、必要、可能、敢于、需要等。,形式变化,情态动词没有人称和数的变化, 第三人称单数的现在时也无变化。有些情态动词有过去式, 有的过去式和它的原型相同。如：can could; shall - should,情态动词的种类,要运用好情态动
2、词，就要首先对情态动词有一个完整的认识，情态动词分为三种情况：1. 只用作情态动词的有：must, can / could, may / might, ought to2. 既可作情态动词又可作实义动词的有：need, dare，have /had to, used to3. 既可作情态动词又为助动词的有：shall / should / will / would,基本用法,1. can, could 表示体力或脑力方面的 “能力”, 或根据客观条件能做某种动作的 “能力”。 用于否定句或疑问句中表示说话人对发生的事情的 “怀疑、猜测、不肯定” 的语气。 could比can 语气更弱。 can
3、 不用于肯定句(除非是经验谈)。,2. may, might may 表示 “允许” 或 “请求”， 在口语中可用can替代, 但may比较正式。 表示说话人的猜测, 认为某一事情 “或许” 或 “可能” 发生，用might指现在的时候语气较为委婉客气或更加不肯定; might 还可表示 “规劝”。,3. must 表示 “必须” 或 “应当”。其否定式表示 “不应该” 或 “不许可”, 语气比较强烈。 表示说话人对事物的推测, 意思为 “一定” 或 “准是”, 语气比may要强得多。 4. have to 表示 “不得不” “必须” 的概念, 比must更含有 “客观条件使得必须如此做”,
4、并有时态变化。,5. shall 作情态动词在陈述句中用于第二和第三 人称, 表示说话人给对方的 “命令” “警告”“许诺” “威胁” “强制”等。 但在疑问句中,主语为第一或第三人称, 表示说话人征求对方的意见或向对方提出 请示。,6. should 表示 “劝告” “建议”, 译为 “应当”。 可表示说话人的感情如 “惊奇” “愤怒” “失望” “不满”等。 表示一种估计、预测的可能情况, 译为 “估计” “按理应当”。,7. will 作情态动词用时在陈述句中可用各人称作主语, 表示其 “意志” “意愿” “决心”等。 在疑问句中用第二人称作主语, 表示说话人向对方提出请示或询问。 有时
5、表示一种习惯动作或状态或自然规律。,would 可用于各人称, 表示过去时间的 “意志” “愿望” 和 决心”。 表示说话人本身的 “意志” 或向对方提出 “请求。 还可以表示过去习惯发生的动作。ought to 表示 “有义务或必要”做某事。 表示劝告。,几组情态动词之间的区别,can / be able to,can 的形式只有can/could两种。 be able to 的形式有am/is/are able to; was/were able to; have/has been able to等多种。 can 表示一般能力。 be able to 表示经过努力后而达到的一定境界。My
6、brother can play table tennis.My brother is able to dive under water for 10 minutes.,shall / will,shall表示允诺; will表示决心或决定。Dont worry. You shall have the tickets for the games. Liu Mei will go and buy the tickets for the games.,在疑问句中，shall用于第一人称或第三人称后，表示提供帮助或给出建议；will用于第二人称或第三人称后，表示询问意愿。,1. Shall we g
7、o swimming this weekend? 2. A group of students are waiting to see you outside. Shall they come in? 3. Will you go hiking with me in the mountains? 4. Will he pay for me ?,mustnt / neednt,mustnt 表示“不准，不许”，语气强烈。 neednt 表示“不需要，没必要”，语气缓和。You mustnt miss this football match. Its very important.You needn
8、t watch the game if you dont want to.Must we clean the classroom? Yes, you must. /No, you neednt.,1. You _buy a gift, but you can if you want to. （2010 湖南）A. must B. mustnt C. have to D. dont have to 解析：dont have to 意为“没有必要”，符 合语境，句意为：“你没有必要买礼物， 但如果你想买的话，你也可以买。”,D,真题解析,2. I have told you the truth.
9、_ I keep repeating it? （2010 江西）A. Must B. Can C. May D. Will解析： must 必须, 一定 can 可以, 能够 may 也许 will 意愿, 倾向性动作, 前半句说我告诉你事实了, 这里用的是现在完成时, 表示过去的动作对现在造成了影响, 既然我已经说了, 我还必须重复一遍吗？,A,3. _ I take the book out? Im afraid not. （2010 四川）A. Will B. May C. Must D. Need解析：表请求可用情态动词can, may, could, might ,表允许用can,
10、may. 句意为：“我可以将这本书带出去吗？”“恐怕不行”。故应选表情请求的情态动词may。正确答案为B。,B,4. I havent got the reference book yet, but Ill have a test on the subject next month. Dont worry. You _ have it by Friday. （2010 江苏）A. could B. shall C. must D. may 解析：shall在第二人称中表示允诺，还可以表示强制，命令，威胁，警告。还有在法律条文中的要求或规定。,B,5. - May I take this boo
11、k out of the reading room?- No, you _. You read it in here. (2010 陕西). A. mightnt B. wont C. neednt D. mustnt解析：考查情态动词。英语中用could，might表示询问或征求意见的问句中，肯定性应答要用can或may来代替could或might，而may或might征求意见的问句否定应答时要用mustnt，故本题选D。,D,6. “You _ have a wrong number,” she said. “Theres no one of that name here.” （2010
12、浙江）A. need B. can C. must D. would 解析：肯定的猜测，用must。,C,1. I thought you _like something to read, so I have brought you some books. A. may B. might C. would D. must,B,2. A computer _ think for itself; it must be told what to do.A. cant B. couldnt C. may not D. might not,A,Practice,3. They will _ run th
13、is machine on their own in three months.A. can B. could C. may D. be able to 4. That big cinema _ seat 2,000 people.A. can B. should C. ought to D. is able to 5. Could I borrow your dictionary? Yes, of course you _. A. might B. will C. can D. should,D,A,C,6. Might I watch TV after supper? Yes, you _
14、.A. may B. must C. might D. can 7. You _ return the book now. You cankeep it till next week if you like.A. cant B. mustnt C. neednt D. may not 8. Johnny, you _ play with the knife. You _ hurt yourself.A. wont; cant B. mustnt; may C. shouldnt; must D. cant; shouldnt,C,B,D,9. Will you stay for lunch?S
15、orry, _. My brother is coming to see me.A. I mustnt B. I cantC. I neednt D. I wont 10. May I pick a flower in the garden? _.A. No, you neednt B. Not, please.C. No, you mustnt D. No, you wont.,B,C,11. Sir, _ he go or stay?Let him go.A. will B. shall C. might D. could,B,12. Ronald _ stay in his small
16、garden for a long time every day in the past.A. could B. might C. should D. would 13. Put on more clothes. You be feeling cold with only a shirt on. A. can B. could C. must D. would,D,C,14. There is someone knocking at the door. it be Tom? A. Can B. Must C. Should D. Ought to 15. Two year ago, my hu
17、sband bought me a bicycle. If you live in town, it is often faster than a car and you worry about parking. A. must not B. may not C. should not D. dont have to,A,D,高考链接,1. Shall I inform him of the change of the schedule right now?I am afraid you _, in case he comes late for the meeting. （2011福建） A.
18、 will B. must C. may D. can,B,2.Why didnt you come to Simons party last night? I want to, but my mom simply _ not let me out so late at night.(2011重庆)A. could B. mightC. would D. should,C,3. No one _ be compared with Yao Ming in playing basketball.Oh, you are really his big fan.(2011湖南)A. can B. nee
19、d C. must D. might,A,4. Hows your new babysitter?We _ ask for a better one, all our kids love her so much. (2011浙江)A. should B. might C. mustnt D. couldnt,D,5. If you _ go, at least wait until the storm is over. (2011辽宁) A. can B. may C. must D. will 6. I _ worry about my weekendI always have my plans ready before it comes. (2011上海) A. cant B. mustnt C. darent D. neednt,C,D,
