状语从句指句子用作状语时,起副词作用的句子。它可以修饰谓语、非谓语动词、定语、状语或整个句子。 根据其作用可分为时间、地点、原因、条件、目的、结果、让步、方式和比较等从句。状语从句一般由连词(从属连词)引导,也可以由词组引起。从句位于句首或句中时通常用逗号与主句隔开,位于句尾时可以不用逗号隔开。 让步状语从句 (1)although与though可以引导让步状语从句,不能与but连用,但可以与yet连用。 Although they are poor,(yet)they are warm-hearted. (2)even if或even though引导让步状语从句,表示“即使”,"“纵然”,用来使人注意下文所强调内容的性质。 I'll get there even if(though)I have to sell my house to get enough money to go by air. (3)no matter后接上who、what、where、how等疑问词,也可以在这类疑问词后面加上ever构成whoever、whatever、wherever、however等。 Don't trust him, no matter what / whatever he says. Whoever breaks the law will be published. No matter how hard the work is, you'd better try to do it well. (4)as也可以引导让步状语从句,要用倒装。 Child as(though)he is, he knows a lot. Much as I like it, I won't buy. Try as he would, he couldn't lift the heavy box. 时间状语从句 (1)as、when、while as表示“当……的时候”,往往和when/while通用,但它着重强调主句与从句的动作或事情同时或几乎同时发生。 She came up as I was cooking.(同时) The runners started as the gun went off.(几乎同时) when:(at or during the time that)既可以表示在某一点的时候,又可表示在某一段时间内,主句与从句的动作或事情可以同时发生也可以先后发生。 It was raining when we arrived.(指时间点) When we were at school, we went to the library every day.(在一段时间内) while意思是“当……的时候”或“在某一段时间里”。主句中的动作或事情在从句中的动作或事情的进展过程中发生,从句中的动词一般要用延续性动词。在when表示a period of time时,两者可以互换。 Please don't talk so loud while others are working. He fell asleep while/when reading. Strike while the iron is hot.(用as或when不可,这里的while意思是“趁……”) (2)引导时间状语从句的连接词除上述外还有: ①till、not…until…、until、before、since Don't get off the bus until it has stopped. He waited for his father until(till)it was twelve o'clock. It will be five years before he returns from England. 推荐阅读: |