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1、时间状语从句,2014.3.14,时间状语从句,引导时间状语从句的普通类从属连词有when(当时),while(在期间),as(当,一边一边),before(在之前),after(在之后),since(从以来),till/until(直到),whenever(无论何时),as soon as(一就)等。,when,由“when”引导的从句:表示主句的动作和从句的动作同时发生,或从句的动作发生在主句动作之前。例:1.I was going out when a visitor came.(我正要出门,有客人来访。)(动词同时发生。)2.I shall tell her the good news
2、 when she comes.(她来时,我将告诉她这个好消息。),while,while 引导的从句:表示“当过程中”,强调某一段时间内主句和从句中谓语动词所表示的动作在同一时期发生。由于while从句表示一个持续的行为,所以从句中要用持续性动词,并且持续性动词常用进行时态。例:Keep an eye on my little sister while I am away.(我不在时,请照看一下我的小妹妹。)While we were watching TV,Jim came in.(我们看电视的时候,Jim进来了。),as,由as引导的时间状语从句,表示时间当.,的时候,一边.一边,随着。
3、其从句的主语与主句的主语往往是同一人或物,如:1.She sang as she worked.她一边工作一边唱歌。此句主从句还可使用进行时 She was singing as she was working.2.I saw him as he was getting off the bus.正当他下公共汽车时,我看见了他。3.As a child,he lived in America.他小时候住在美国。4.You will grow wiser as you grow older.随着你年令的增长,你会变得更聪明。,before,before引导的从句:一般表示主句的动作发生在从句动作之
4、前。例:I didnt know any English before I came here.(我到这儿来之前,一点英语都不懂。)(虽然主句的动作发生在从句动作之前,主句和从句中动词都可用过去时。)I had written my report before my father came back.(我父亲回来之前,我已写完我的报告。)(为了表明主句的动作发生或完成在从句动作之前,主句动词一般用过去完成时,从句中动词用过去时,以区分动作的先后。),after,after引导的从句:表示主句的动作发生在从句动作之后。例:After he locked the door,he left.(他锁上
5、门,就走了。)(虽然从句的动作在前,主句的动作在后,但表示过去发生的连续动作,都可用过去时。)After he had finished his work,he played a game of chess with his friend.(他做完工作后,和朋友下了一盘棋。)(“做完工作”在前,“下棋”在后,为了表明动作的先后,从句中的动词一般用过去完成时,主句中的动词用过去时。),since,6.since引导的从句:表示“自从以来“,从句中的动词一般表示动作的起点,用过去时。主句中的动词表示动作延续的情况,一般用现在完成时。如果主句中的动词表示的不是延续的动作而是表示目前的状态,可用一般现
6、在时。例:Since he met this good friend,he has made great progress in his studies.(自从遇见了这个好朋友,他已在学习上取得了巨大的进步)It is twenty years since she joined the Party.(她入党二十年了。)(主句中的动词表示的不是延续动作,而是状态,用现在时。),until,until 引导的从句:a表示“直到,主句和从句都用肯定式b表示“直到才”,主句用否定式,从 句用肯定式。例:They worked until it was late.(他们一直工作到天黑。)She didnt go to bed until she(had)finished her homework.(她一直到写完作业才睡觉。),as soon as,as soon as 引导的从句表示“一就”。例:As soon as she came to the classroom,she began to read English.(她一到教室,就开始读英语。),