人教课标版高一英语（必修3）unit 2 gramma.ppt

人教课标版 高一 必修 3 Unit 2 Grammar Find the sentences containing modal verbs in the reading passage. Then usually by lunchtime they would all be sold. What could have happened? Nothing could be better Something terrible must have happened if He could not believe his eyes. Perhaps he should go to the library and find out. He had better do some research! Even though her customers might get thin after eating Yong Huis food They would become tired very quickly. Modal verbs a. should, ought to都可表示“应该”。 ought to用于表示按道理应当，常指客 观的义务或责任，大多数情况下可用 should代替，但比should语气重。 I should help her because she is in trouble. You ought to take care of the baby. b. 表示劝告、建议或命令时，should和 ought to可通用，但在疑问句中常用 should。ought to的否定式为oughtnt to或ought not to。 You should / ought to go to class right away. Should I open the window? What should we do next? c. should, ought to都可表示推测。 He ought to / should be home by now. This is where the oil ought to / should be. should 和ought to 后面跟动词不定式的完成 式, 其肯定句表示“过去应该做而未做”, 其否 定句则表示 “过去不该做但做了”。 You should/ought to have made the decision a week ago. I shouldnt have made such a foolish mistake. 多数情况下，ought to可与should互换使用。 ought to的反意疑问句用shouldnt替代。 注意 You ought to have helped him with his English, _? A. wont you B. ought not you C. shouldnt you D. wouldnt you 2. must和have to must的用法 1) 表示主观的义务和必要, 主要用于肯 定句和疑问句, 意思为 “必须，得 ，要”；由must引起的疑问句， 肯定回答要用must或have to, 否定回答要 用neednt或dont have to, 意思是“不必” ； must的否定形式mustnt表示禁止，意 思是“不能，不许”。如： Must I finish the task right now? 我现在必须完成这个工作吗？ Yes, you must. / Yes, you have to. 是的。 (No, you neednt. / No, you dont have to. 不，不必。) You mustnt come here without permission. 未经允许，你不能来这儿。 have to 的用法 1) must表示一种主观的需要，而have to 表示一种客观的需要，意思是“不得不” 。 如： I have to attend an important meeting this afternoon. 今天下午我不得不参加一个重要的会议 。 Mother is out, so I have to look after the shop. 妈妈不在家，因此我不得不照看商店 。 2) have to 的否定形式是dont have to, 相当于neednt。如： They dont have to buy a computer at present. 他们目前没有必要买电脑。 【考例】The boss has given everyone a special holiday, so we _ go to work tomorrow. (上海 2007春) A. cant B. mustnt C. neednt D. shouldnt 【点拨】考查情态动词。根据题意, 可知 这里表示“没有必要”, 故只能选C项。 【考例】What do you think we can do for our aged parents? You _ do anything except to be with them and be yourself. (重庆 2007) A. dont have to B. oughtnt to C. mustnt D. cant 【点拨】根据题意“除了和他们呆在一起 做你自己外, 没有必要做任何事情。”可 知这里选择dont have to表示“不必”。 故选A项。 3. must和need a. need作情态动词时, 只能用于疑问句和 否定句。构成否定句和疑问句时不借 助于助动词do。 Need I finish the work today? Yes, you must. / No, you neednt. b. must的肯定形式表示“必须”，否定式 表示“禁止、严禁”。 You must come here. You mustnt take the book away from the library. 用下列图片造句。 做适当的运动 You should do some sports. 慢慢地进食，并有助消化。 You ought to eat slowly and its good for digestion. You should help to set the dinner table. You should keep your room clean. We must listen to the teacher carefully. We mustnt eat in class. You ought to hand on the homework on time. You shouldnt be late for school. We should ask question actively. We shouldnt make noise in class. Make sentences 1. 你每天最少要练习一小时口语。 You must practise speaking English at least an hour a day 2. 我每天不得不练习一小时口语！ I have to practise speaking English an hour a day! 3. 你应该每天练习不止一小时。 You ought toshould practice English for more than an hour. 4. 你应该读一下这个。它写得很好。 You ought toshould read this. Its very good. 5. 你必须读这个。写得精彩极了！ You must read this. Its marvelous! Please choose a proper phrase and according to the situations complete the sentences by using should (not) or ought (not) to. 1. Lisa needs a change. She _. 2. My salary is very low. You _. should/ought to take a few days off should look for a new job 3. Nick always has difficulty getting up. He _ _. 4. What a beautiful view! You _. 5. Billys room isnt very interesting. He _ _. ought not to /shouldnt go to bed so late should take a photo shouldnt/ ought not to use her car so much Choose suitable modal verbs below to complete the following dialogues. ought/oughtnt to should/ shouldnt mustnt neednt (dont) have to will can/ cant 1 Sam: How can I grow thinner, Mum? Mum: Well, you _ eat food with plenty of fibre that helps you digest better. And you _ stop drinking cola or eating sweet food. have to should Sam: Does it mean I _ eat my favourite fried chicken any more? Mum: Not exactly, if you love fried chicken, you _ give it up. Just eat it less often. You _ worry too much: a little fried chicken _ do you good! shouldnt neednt dont have to/ neednt/ shouldnt will 2 Doctor: You are sick because youve eaten poisonous mushrooms. Where did you get them? Lucy: I picked them in the forest. I know we _ eat fresh vegetables. Doctor: Oh, but you _ eat them until youre sure they are not poisonous. Lucy: Thank you, doctor. Ill be more careful next time. have to mustnt 3 Charles: I wish I could see things clearly in the dark. Tom: Eating carrots _ help you see better. You _ eat some every day. ought to should 1. _ to discuss something with someone so that you can make a decision together 2. _ to change food that you have just eaten into substances that your body can use 练习坊 I. 根据下列英文解释写出所缺的单词。 consult digest 3. _ a long pointed orange vegetable that grows under the ground 4. _ containing poison or producing poison carrot poisonous 1. For a long time, Ive built my business with people who are _ (精力旺盛的), creative, and happy about their work. 2. This rich food doesnt _ (消化) easily. energetic digest 根据下列各句句意及所给单词的汉语 提示, 写出各单词的正确形式。 3. The dish of boiled beef and _ (胡萝卜) tastes good. 4. An increasing number of people are _ (请教) their accountants about the tax laws. 5. This medicine is _ (有毒 ) if taken in large quantities. carrot consulting poisonous must; oughtnt to; dont have to; couldnt; mustnt; neednt; cant; have to II. 用所给的情态动词填空 。 1. You _ go on working because you look so tired now. 2. The weather turned out to be fine yesterday. I _ have had the trouble to carry my umbrella with me. oughtnt to / dont have to neednt must; oughtnt to; dont have to; couldnt; mustnt; neednt; cant; have to 3. If you earn more than 5,000, you _ pay tax. 4. You _ play now! You shall finish your homework first! 5. I know things are hard with you, but you _ try to get over the difficulties. have to mustnt must / have to must; oughtnt to; dont have to; couldnt; mustnt; neednt; cant; have to 6. I didnt see her at the meeting this morning; she _ have spoken at the meeting. couldnt / cant 1. I thought you _ like something to read, so I have brought you some books. A. may B. might C. would D. must 2. Where is my pen? I _ it. A. might lose B. would have lost C. should have lost D. must have lost 高考链接 3. I didnt hear the phone. I _ asleep. A. must be B. must have been C. should be D. should have been 4. -Is John coming by train? -He should, but he _ not. He likes driving his car. (2002高考题） A. must B. can C. need D. may 5.