1、单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,单击此处编辑母版标题样式,*,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,孟 溪 中 学,何鑫,制作,2014,年,4,月,when,，,whil
2、e,，,as,引导时间状语从句的区别,when,，,while,，,as,显然都可以引导时间状语从句，但用法区别非常大。,一、,when,可以和,延续性动词,连用，也可以和,短暂性动词,连用；而,while,和,as,只能和延续性动词连用。,Why do you want a new job when youve,got,such a good one already,？（,get,为短暂性动词）,你已经找到如此好的工作，为何还想再找新的？,Why do you want a new job,when,youve,got,such a good one already,？,（,get,为短暂性
3、动词）,你已经找到如此好的工作，为何还想再找新的？,The students took notes,as,they,listened,（,listen,为延续性动词）学生们边听课边做笔记。,二、,when,从句的谓语动词可以在主句谓语动作之前、之后或同时发生；,while,和,as,从句的谓语动作必须是和主句谓语动作同时发生。,1,从句动作在主句动作前发生，只用,when,。,When he had finished his homework,，,he took a short rest,（,finished,先发生）当他完成作业后，他休息了一会儿。,When I got to the air
4、port,，,the guests had left,（,got to,后发生）当我赶到飞机场时，客人们已经离开了。,2,从句动作和主句动作,同时发生,，且,从句,动作为延续性动词时,，,when,，,while,，,as,都可使用。,When,While,As we were dancing,，,a stranger came in,（,dance,为延续性动词）当我们跳舞时，一位陌生人走了进来。,When,While,As she was making a,phonecall,，,I was writing a letter,（,make,为延续性动词）当她在打电话时，我正在写信。,3,当
5、主句、从句,动作同时进行,，从句动作的,时间概念淡化,，而,主要表示主句动作发生的背景或条件时,，,只能用,as,。这时，,as,常表示“随着,”,；“一边,，一边,”,之意,。,As the time went on,，,the weather got worse,（,as,表示“随着,”,之意）,The atmosphere gets thinner and thinner as the height increases,随着高度的增加，大气越来越稀薄。,As years go by,，,China is getting stronger and richer,随着时间一年一年过去，中国变
6、得越来越富强了。,The little girls sang as they went,小姑娘们一边走，一边唱。,4,在将来时从句中，常用,when,，且,从句须用一般时代替将来时,。,When the manager,comes,here for a visit next week,，,Ill talk with him about this,下周，经理来这参观时，我会和他谈谈此事。,三、,when,用于表示“一,就,”,的句型中（指过去的事情）。,sb,had,hardly/scarcely,done,sth,when,Hardly,Scarcely had,sb,done,sth,when,我刚一,闭上眼,，就有人在,敲门,了。,I had hardly,scarcely closed my eyes when someone knocked at the door,Hardly,Scarcely had I closed my eyes when someone knocked at the door,
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