when_while_as引导时间状语从句的区别.ppt

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,，,while,，,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 airport,，,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,