Unit 2 Healthy eating-Grammar

Period 4 Grammar Modal Verbs

The first wealth is health . 健康是人生第一财富。 A light heart lives long. 豁达者长寿。 Early to bed and early to rise makes a man healthy , wealthy and wise. 早睡早起会使人健康、富有和聪明。

Without health no pleasure can be tasted by man. 没有健康就没有乐趣。 Good health is over wealth. 健康是最大的财富。

What should/shouldn’t we do to keep healthy? What ought we to do to keep healthy?

If you’d like to give advice or opinions, you can use

should/ ought to/ had better do

Good habits can help us to keep healthy and bad ones can cause diseases. There is a serious disease called H1N1 flu these days. It spreads easily among people in spring and autumn. The flu is a serious disease, but we don’t have to be afraid of it. We can do something to prevent it. But how? We ought to keep the air fresh all the time. We ought to keep away from crowded places. We’d better drink more water every day.

You should go to school right away. It’s eight o’clock now. He should be at work. It seems so unfair this should happen to me. 表惊讶：竟然 You should have reminded me of the meeting. 表责备，谴责 What should we do now? 用于第一人称疑问句，询问对方的意愿

What kind of food must we eat to be strong?

must / have to

Must I finish the task right now?

Yes, you must/ you have to. No, you needn’t / you don’t have to.

She called me yesterday evening but I didn’t hear it. I _________________ (be) asleep. must have been

1. --Will you stay for lunch? B --Sorry, _____. My brother is coming to see me. A. I mustn’t B. I can’t C. I needn’t D. I won’t C 2. --May I pick a flower in the garden? -- ________. A. No, you needn’t B. Not, please. C. No, you mustn’t D. No, you won’t. 3. You ______ return the book now. You can keep it till C next week if you like. A. can’t B. mustn’t C. needn’t D. may not 4. John, you B play with the knife, you __ hurt yourself. __ A. won’t ; can’t B. mustn’t ; may C. shouldn’t ; must D. can’t ; shouldn’t

表示否定的情态动词的用法:mustn’t needn’t shouldn’t can’t 不准, 禁止 没必要 ( = don’t have to )

不应该 ( = ought not to )不能，不可能

Could you use them to make sentences?

What modal

verbs have you learned?

can/could may/ might will/ would shall/ should had better must have to need ought to dare

1. 表示“能力”的情态动词的用 法

can, could (be able to)

*can / could 只能表示现在或过去的能力 * be able to 能用于各种时态相当于manage to do sth. / succeed in doing sth. 1.He ___________ go to the party yesterday was able to evening in spite of the heavy rain. 2. Although he can’t _____swim, he __________ cross was able to the river.

2. 表示“许可”的情态动词 may / might, can / could1. ---____ I go out to play, mum? -

--No, you___. You should do your homework first. A. Might; wouldn’t B. Can; needn’t C. Can; can’t D. Need; mustn’t 2. --- Could I call you by your first name? --- Yes, you____. A. will B. could C. can D. might

3. 表示“请求”的情态动词的用 法will / would, shall/should

* 均可表示将来。 过去时为 should, would. * will, would 可表示意愿、常出现的动作。在疑问句中表示请求和建议.

4.表示“推测，可能性”的情态动词must, could , may, might, can’tcan 表示推测时，只能用在否定句或疑问句中。It’s so late. Can Tom be reading? 这么晚了，汤姆还在看书吗？ 这个人不可能是玛丽， 她生病了。 It couldn’t be Mary. She had fallen ill.

情态动词能表示时态吗？1. 表示对现在的推测

2. 表示对过去的推测3.表示对将来的推测

表示推测——情态动词的重要用法情态动词 肯定的推测 对将来 + V. 常见must be + V. 对现在 对过去 + V. + have done + be doing

must可能的推测

may, might否定的推测

+ V. + have done + be doing 可以用not表示“可能不” + V. + be doing + V. + be doing + have done

can’t, couldn’t

+V.

疑问的推测

+ V.

+ have done

can, could

should You look tired. You _______ go to bed now.

You _______________ believe everything you shouldn’t/can’t read on the Internet.

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