牛津上海版高中三年级第一册英语 Unit 2 Society and change 状语从句 教案

Unit 2 Society and change Teaching aims and demands 掌握各种状语从句的基本用法。 Teaching important points and difficulties 各种状语从句的概念和用法。 Teaching procedures Step1．状语从句的基本概念 1．状语从句的定义： 在复合句中由从句表示的状语称作状语从句，它可以用来修饰谓语（包括非谓语动词）、定语或状语，或是整个句子。状语从句通常由一个连词引起，也可以由一个起连词作用的词组引起，有时甚至不需要连词直接和主句连接起来。 状语从句一般分为九大类： 时间状语从句、地点状语从句、原因状语从句、目的状语从句、结果状语从句、条件状语从句、方式状语从句、比较状语从句、让步状语从句。 2．状语从句的分类： (1) 时间状语从句 由下列连词引导：when, while, as, before, after, once, till, until, once, as soon as, now that, hardly…when, scarcely…when, no sooner…than,有一些表示时间的副词（短语）或名词短语也可引导时间状语从句。如：directly, instantly, immediately, by the time，the moment, the second, the minute, the instant, every time, each time, next time, the last time等 注意点如下： 1)when, while, as引导的时间状语从句 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。所以常译作“一边……一边”。 John sings as he works. ① She came up as I was cooking.(同时) ② When I was walking down the street, I came across an old friend of mine. 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。 ①It was raining when we arrived．(指时间点) ②When we were at school, we went to the library every day.(在一段时间内) ③When we arrived there, the film had already begun.(先后发生) While强调一段时间里，仅表示从句和主句的动作同时发生，并且有延续意义，该从句中的动词一般要用延续性动词，从句中常用过去进行时态或一般过去时态；在when表示a period of time时，两者可以互换。 ①Please don’t talk so loud while/when others are working. ②He fell asleep while/when reading. ③While they were watching TV, I was preparing myself for the coming examination. Strike while the iron is hot. (不可用as或when，这里的while意思是“趁……”) As his hands dropped he dropped with it, and I laid him down, dead. 当When引出的时间状语从句为系表结构，而且其主语和主句的主语一致，其表语又是一个名词时，就可以用 as 引导的省略句来代替。 When he was a young man (=As a young man) he was fond of hunting. (2) before状语从句的重点句型 It will (not ) be a period of time before 还要……才，要不了多久就…… It was (not) 过了……才 没多久就…… ①It was a long time before I got to sleep. ② It wasn’t long before he told me about the news. ③不等……就 在……之前： The telephone rang off before I could answer it. ④刚……就： He hardly entered the room before he heard the telephone ring. ⑤先……再： You can have a few days to think about it before you make your decision. (3) since 引导的从句用延续性动词的过去式（包括过去完成时），则从句的动作已经结束,从句意思是否定的。如果从句的动词是延续性动词的完成时态，从句意思是肯定的。 It is /has been a period of time 延续性动词的过去式 自从该动作结束已多长时间 延续 ... ...