用一个句子作状语,这个句子就是状语从句。状语从句通常用来修饰句子、动词或形容词,表示时间、地点、条件、原因、目的、结果、方式、比较等。引导状语从句的连词叫从属连词。
在句中用作方式状语的从句叫方式状语从句。引导方式状语从句的从属连词主要有as,as if,as though等。
(1)as引导方式状语从句意为“按照;像……”;as引导的方式状语从句通常位于主句后,但在(just)as ...so ...结构中位于句首,这时as从句带有比喻的含义,意思是“正如……;就像”,多用于正式文体。如:
You should do as I told you.你应当按我告诉你的去做。
You must try to hold the tool as I do.你必须像我这样拿工具。
Just as we sweep our rooms,so we should sweep backward ideas from our minds.正如打扫房屋一样,我们也要扫除我们头脑中落后的东西。
(2)as if引导方式状语从句意为“仿佛;好像”。
I remember the whole thing as if it happened yesterday.整件事我记得很清楚,就仿佛是昨天发生。
He behaves as if he were a child.他的举止就像个孩子。
(3)as though引导方式状语从句与as if意思相同,意为“仿佛;好像”。如:
He closed his eyes as though he were too tired.他闭着眼睛,好像太累了。
He looked about as though he was in search of something.他四下张望,好像寻找什么。