概要：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 (常缩写为'
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 (常缩写为'd 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 D. need