状语从句按其意义和作用的划分.doc

状语从句按其意义和作用可分为:a)时间状语从句b)地点状语从句c)原因状语从句d)目的状语从句e)结果状语从句f)条件状语从句g)方式状语从句h)比较状语从句i)让步状语从句2.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, hardly…when, no sooner…than等引导。如：When he was still a young man, he was forced to leave his homeland for political reasons.注意：a)when, as, whilei.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）ii.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.iii.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 music.While we were watching TV, he was writing a composition.while也可做并列连词，表示对照的含义，意思为“而”。如：He is tall while his brother is short.当when, as, while表示“在…一段时间里”，主从句的动作同时发生时，可以换用。如：While (When或As) we were discussing, Mr. Smith came in.b)如果when和before引导的从句位于主句之后，有时不能译成“当…时候” 和“在…之前”，而要译成“就”、“才”、“这时”等。如：The struggle lasted four years before the North won in the end.He almost knocked me down before he saw me.She had not been married many weeks when the man saw her and was struck by her beauty.I was walking in the street when I saw him.c)by the time, each time, every time, immediately, the moment, the instant, the minute, soon after, shortly after都可以作为连词，引导时间状语。如：By the time he was fourteen, he had taught himself advanced mathematics.Each time he came, he would call on me.You must show him in immediately he comes.I recognized him the moment I saw him.d)by the time 的用法i.by the time+现在时，主句用将来完成时．例如：By the time he arrives, we will already have left California.ii.by the time+一般过去时，主句用过去完成时．例如：By the time he arrived, we had already left California. e)till和untili.如果主句谓语动词是持续动词，通常用肯定式的主句，表示“直到…为止”。如： I worked till (until) he came back.ii.如果主句谓语动词是瞬间动词，则用否定式的主句表示“直到……才”。