状语从句 状语从句在主从复合句中修饰主句中的动词,形容词或副词,按意义可分为时间、地点、原因、目的、结果、条件、方式、比较、让步等状语从句
从句的位置放在句首,也可放在句末
放在句首时,从句后面常用一个逗号,放在句末时,从句前一般不用逗号
( 1 ) when, as, while (从属连词) when 即可引导持续性动作,又可引导短暂性动作
它可以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
如: When I was a boy, I used to go to the seashore on Sundays
(同时) When the lesson was over, we began our writing
(从句动作在前)1 、时间状语从句:引导时间状语从句的从属连词有: when, while, as, whenever, before, after, since, till, until, as soon as, once,the moment, immediately, no sooner…than, hardly…when, by the time, every time, last time… 等引导
as 引导持续性动作,侧重主句和从句的动作同时发生
He hurried home, looking behind as he went
I saw your sister as she was getting on the bus yesterday
He sang as he walked
While :指的是“在某一时间里”,“在… 期间”,从句里的动作必须是持续性的,它也强调主句和从句动作的同时发生,往往侧重主句和从句动作的对比
如: While he was in London, he studied mus