Unit 4 Don't eat in class. 第2课时考点讲解 （19张PPT）

Unit 4 Don’t eat in class. R 七年级下册 第二课时 Lead in Do you have any family rules? What are your family rules? Family rules Be friendly. Save water. Clean the bedroom on Saturdays. Don’t get up late on Sundays. Don’t waste food. Don’t talk loudly. Don’t keep animals. Lead in Language points 1.情态动词must的用法 (1)表示有做某一个动作的必要和义务，它的意思是“必须、应该”。 情态动词must与have to Language points You must do your homework. Language points (2)表示有很大把握的判断或者推测，它的意思是 “一定、准是”。 例:那个高个子男人一定是你的爸爸。 The tall man must be your father. Language points (3)以must开头的一般疑问句，它的否定回答用 needn’t (不必要),不用mustn’t ,mustn’t 常用于否定句中，表示“不允许，禁止”。 例:你的车不允许停在这儿。 You mustn’t park your car here. Language points 2.情态动词have to的用法 have to表示客观需要做的事情，意思是“必须， 不得不”。 (1)have to后接动词原形，意为“必须做……；不 得不做……”。 例: 我不得不离开了。 I have to leave. Language points (2)have to有人称、数和时态的变化，其第三人称 单数形式为has to。 例: 他不得不做作业。 He has to do his homework. Language points (3)含有have to, has to的句子变疑问句或否定句需 分别借助助动词do, does 。 例: 他们必须早起吗？ Do they have to get up early? Language points We don’t have to come to school every day. 我们不必每天来学校。 have to为固定短语，意为“不得不，必须”， 其后接动词原形，有时态和人称的变化。 have to的否定形式是：主语+don’t + have to+动词原形+其他（一般现在时，当主语是第三人称单数时,用doesn’t have to，一般过去式用didn’t have to) Look and say No talking! Can we talk in the library? We can’t talk in the library. Don’t talk! We must keep quiet in the library. We have to keep quiet in the library. Look and say No eating! Can we eat food in the library? We can’t eat food in the library. Don’t eat food! We must eat nothing in the library. We have to eat nothing in the library. Look and say No bringing umbrellas! Can we bring umbrellas in the library? We can’t bring umbrellas in the library. Don’t bring umbrellas! We must left our umbrellas at the door. We have to left our umbrellas at the door. Look and say No listening to music! Can we listen to music in the library? We can’t listen to music in the library. Don’t listen to music! We must listen to nothing in the library. We have to listen to nothing in the library. Practice 1.My sister _____ be at school by seven o’clock. 　A. has to　　　 B. have to 　　　 C. had to 　　　D. must to 2. It’s raining all day, so my brother _____ stay at home. 　A. must 　B. have to　　C. must to 　D. has to Practice 1.She has to do the dishes.（改为一般疑问句） _____ _____ _____ _____ do the dishes? 2.Lucy has to wear sports shoes for running. （否定句） _____ 3.I have to clean my room. 同义句：_____ 对划线部分提问： _____ Does she have to Lucy doesn't have to wear sports shoes for running. I must clean my room. What do you have to do?　 Class summary Unit 4 Don’t eat in class. 1.—Does he have to wear a unif ... ...