九年级英语9AUnit5 Grammar学案.doc

九年级英语9AUnit5 Grammar学案 1.should 和ought to 与must区别 用should/ought to 可以表示”劝说”或”督促”, 和must 一样, 但三者语气强弱不同。 用should 语气比较肯定一些, 说话人的主观信心要强烈一些。含有责任的意思。 用ought to则口气上不那么坚定。 用must则在口气上最强烈,含有责任的意思。例如: You must do your homework.? You should speak to your parents politely.. I ought to write to him today. 2.must 与have to? must表示”必须”,侧重于说话人的主观意志。 have to 表示”必须”, 侧重于客观的需要,含有”不得不”的意味 。 3.had? better ,是一固定词组, 表示”最好”, 用于表示对别人的劝告、建议或表示一种愿望。 had better 后面加动词原形,即 had better do sth.不论主语是第几人称, 句子无论是何种时态,had better 形式不变。had better 的否定形式为had better not do sth 表示”最好不要做……”。如:You’d better not miss the last bus. You’d better not play on the road. It’s dangerous. You’d better put on the coat. It’s cold outside. 4.Why not…?/Why don’t you …? 这两种句型结构常用于说话人向对方提出一个建议,意思是”不……?”; “为什么不……?” Why not…?/ Why don’t you …? 后面必须跟动词原形。如: Why not go swimming?=Why don’t you go swimming? Why don’t you go out for a walk? =Why not go out for a walk? 练习: 一单项选择 1. My mother was ill. I ______ stay at home to look after her. A. must ? B. have to ?? C. could ?? D. can 2. ---____ go shopping with your father?--- That’s a good idea. A. Why don’t? B. Why not?? C. Do ? D. Does 3. You ___ give up smoking. ?? A. would better?? B. had better? C. would better to? D. had better to 4. Why don’t you _____climbing with us tomorrow? A. to go B. going ? C. go D. goes 5. Cars, buses and bikes ___ stop when the traffic lights changes to red.? A. can B. may ?? C. must?n bsp; D. need 6. It’s too hot. Perhaps you ______ swimming this afternoon. ? A. must? go B. should go??? C. may go??? D. can go 7. To make our hometown more beautiful, you __throw rubbish into the river. ?? A. needn’t B. mustn’t C. must D. need 8. How interesting the