情态动词
（一）情态动词的特征： 特征 有一定的词义，均没有人称和数的变化（have to，be able to 除外）。 不能单独作谓语，必须和行为动词或系动词连用，构成谓语。 例句 He can speak Japanese very well. 他能够把日语说得很好。 She can’t be here. 她不能在这里。 I have to look after my father. 我必须照顾我的爸爸。 You mustn’t go alone. 你决不能独自走。 具有助动词的作用，可用来构成否定句，疑问句和用于简单的回答。
（二）情态动词的分类 情态动词 can/could may/might will/would shall must need
含义 可能，能够 可能，可以 愿意 请求，许可 必须 需要 使用人称 各种人称 各种人称 第二人称 第一、第三人称 各种人称 各种人称 （三）情态动词的用法 Can 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，此时may和must均不可代替它 Eg:She can swim fast, but I can’t .表示许可，常在口语中 You can use my dictionary. 表示推测，意为“可能”，常用于否定句和疑问句中，此时can’t译为“不可能” —Can it be our teacher? —No, it can’t be our teacher. He is on a visit to the Great Wall. Could can的过去式，意为“能、会”，表示过去的能力 He could write poems when he was 10. could在疑问句中，表示委婉的语气，此时could没有过去式的意思（注意回答时用can） — Could I use your pen? —Yes, you can may 表示请求、许可，比can正式 在回答由may引导的问句时，作肯定回答时一般可仍用may来回答或用Yes, please/can. / Certainly./Sure./Of course. ；作否定回答时根据说话人的语气由强到弱分别选用must not（mustn’t）（禁止）/ can’t/had better not（最好别）等情态动词。 —May I go out？—No, you mustn’t. —May I open the window? —Certainly./Sure./Of course. 表示推测，谈论可能性，意为“可能，或许”，一般用于肯定句中 It may rain tomorrow 表示希望、祈求、祝愿，常可译为“祝愿”。通常是用may +主+V May you be happy!祝你幸福！ May you succeed！祝你成功！ Might may的过去式，疑问句中might也可指现在的时间，语气比may更委婉。 Might I ask for a photo of your baby 表示推测时。可能性低于may。 He is away from school. He might be sick. must表示主观看法，意为“必须、一定” mustn’t意为：“不许、不准”，表示禁止 You must stay here until I come back. You mustn’t smoke in public.公共场合禁止吸烟。 对must引导的疑问句，肯定回答为must/have to，否定回答为don’t have to/needn’t —Must I stay here for an hour ? —No, you needn’t./ No, you don’t have to. must表示有把握的推测，用于肯定句 This book must be Li Ping’s because his name is on the cover. need need作情态动词时，表示需要、必须，主要用于否定句和疑问句中 I needn’t wear a coat.。 I don’t think you need worry. 用need提问时，肯定回答用 must，否定回答don’t have to/needn’t。 —Need I stay here any longer? —Yes, you must .。 —No. you needn’t ./don’t have to need还可以作实义动词，此时有人称、数和时态的变化，如果是人作主语后边多接动词不定式。 We need some help. I don’t need things like that. Shall shall表示征求对方意见（多用于第一、三人称）. Shall we go out for a walk? 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 Should shall的过去式 If I should fail I would try again .should意为“应该”，可表示劝告、建议、义务、责任等 You should finish your homework early. We shouldn’t waste time. Will will表示意愿、意志、打算，可用于多种人称。 Must I will help you if I’m free this afternoon. Would 表示过去时间的意愿 would We invited him to the party but he wouldn’t come. Will/would用在第二人称的一般疑问句中，主要表示征求对方的意见 Would you please look after my dog while I am away? Will you please help me carry the box?
情态动词易混淆点
一: can和be able to:
两者表示能力时用法相同，但can只有原形“can”和过去式“could”两种形式，在其他时态中要用be able to来表示。另外be able to常常指经过努力，花费了时间和劳力之后才能做到某事。
如：Jim can’t speak English.吉姆不会说英语。 He could speak English at 5.他五岁时就会说英语。
We’ll be able to see him next week.下星期我们将会见到他。 He has been able to drive.他已经会开车了。
I’m sure you’ll be able to finish it quickly.我相信你能迅速地完成。
We were able to reach the top of the mountain at noon.我们能在中午到达山顶。
二． must和have to两者都表示“必须”的意思,但must含有说话人主观上的看法、态度；have to则表示客观上的需要。
You ______ wear sports shoes when you climb a mountain.
A. can’t B. shouldn’t C. mustn’t D. have to
It rained heavily, so we ____ stay at home watching TV or surfing the Internet all day. A. could B. had to C. must
情态动词练习
1.—Must we finish giving out the posters today?
—Yes, we _______. It can’t be put off any longer. [太原] A. can B. may C. must
2.—I didn’t pass the math test. I think I have spent too much time playing computer games recently.
—I agree. You_______ play like that any more. [河南]
A. needn’t B. mustn’t C. may not D. wouldn’t 3.When traffic lights are red. We _________stop and wait. [南京]
A. may B. can C. must D. might. 4.—I really like playing computer games!
—I’m afraid you ________stop，for your study and your health. [宜昌] 5.—Could I borrow your dictionary? —Of course you ____________.[陕西] A. can B. must C. should D. will 6.—Listen! Is Tom singing in the classroom?
A. am
B. will
C．may
D．must
—No. It ________be Tom. He has gone to Paris. [长沙市] A. may not B. needn’t C. can’t
7.—Mary, ________ you speak Chinese? —Yes, only a little. [北京] A. must B. need C. may D. can
8.Schools _________allow students at least one hour a day for sports. [安徽] A. would B. might C. should D. could 9.You ________be tired after working for eight hours without a rest. [广东] A. can B. may C. must D. need 10.—Look at the boy running on the ground．Is it Davis?
—It ____be him．I saw him go to the teacher’s office just now．[黄冈] A. must B. can’t C. could D. might
含有情态动词的一般疑问句回答
1，,—Must I answer this question in English? —No, you ______.
A. mustn’t B. needn’t 课后练习 C. can’t D. shouldn’t 2.—May I watch TV for a while？
—No, you______. You have to finish your homework first. A. shouldn’t B. needn’t C. mustn’t D. won’t 3.—______ I have a ticket, please?
—Sorry, sir. All the tickets were sold out ten minutes ago.
A. May B. Need C. Must D. Should 4.—______we clean the classroom at once?
—No, you _______. You ______ clean it after school. A. Must; needn’t; may B. Must; mustn’t; can C. Shall; can’t; must D. Need; mustn’t; may 5.—Whose schoolbag is this?
—It ____ be Mary’s. It has her name on it.
A. can B. may C. will D. must 6.—May I play computer games for a while, Mum?
—No, you______. You have already played for two hours.
A. shouldn’t B. needn’t C. mustn’t D. won’t 7.—Will you stay for some more days?
—Sorry, I_____. My mother called to ask me to go back at once. A. mustn’t B. may not C. can’t D. wouldn’t 8.----Must I finish the homework now?
— No, you ______. But you must finish it before next class. A. can’t B. may not C. mustn’t D. needn’t 9.— Would you like to go to the park with me? — I’d love to, but I’m afraid I _______.
A. can’t B. mustn’t C. needn’t D. shouldn’t
（word完整版）初中情态动词用法
