专四语法：PART5 状语从句.docVIP

PART5 状语从句. Introduction状语从句也是四级词汇和句法部分考查的重点之一，就状语从句而言，主要是根据主从句的关系判断连词的使用。因此，在准备状语从句时，主要任务是弄清楚各种状语从句的连词。 1．时间状语从句的连词 表示时间的连词有when, while, as, by the time, before, after, since, till/until, as soon as，有些名词短语也可以引导时间状语从句，如the moment, the instant, each time，有些是固定句型如：no sooner … than hardly/scarcely …when。 ① as强调同时，也表示一边……，一边……，while表示主句动作发生在从句的过程之中，要求从句谓语动词为状态动词或持续性动词，when的使用则比较简单，相当于汉语的当……时候。如： Doing your homework is a sure way to improve your test scores, and this is especially true ____ it comes to classroom tests. A.when B.since C.before D.after 四个选项都表示时间，但根据主从句间的关系可以判断答案 为A。 ② 注意when的特殊句型 下列句型中when连接的不是时间状语从句，但考试中却常与其它时间状语从句的连词一块出题。 were/was doing something when … were/was about to do something when … had just done something when … 四级考题中不乏对上述结构的考查，如： I had just started back for the house to change my clothes ___ I heard voices. A.as B.when C.after D.while I felt somewhat disappointed and was about to leave ___ something occurred which attracted my attention. A.unless B.until C.when D.while ③ 注意no sooner … than ….和hardly/scarcely …when句中的时态。 No sooner had I got to the bus stop than the bus started. Hardly had I got to the bus stop when the bus started. ④ 注意not … until 中时间状语可以提前。如 :____ quite recently, most mothers in Britain did not take paid work outside the home. A.Before B.Until C.From D.Since 比较常见的提前方式是将not until….提至句首，后面用肯定形式，主谓倒装。本题可以改成，Not until quite recently did most mothers in Britain take paid work outside the home.这时，句子采用主谓倒装结构，应注意。 ⑤ 在对名词短语做连词引导时间状语从句时，常与名词构成的其它短语相区别。如： You see the lightening ___ it happens, but you hear the thunder later. A.the instant B.for an instant C.on the instant D.in an instant 能够引导时间状语从句的是名词the instant，而不是由其构成的介词短语。 ⑥ 注意含有时间状语从句的固定句型，如It wont be long before … 和It is …since两类句型。It wont be long before可以有三个变体，即：It was (not) + 一段时间 + before，It wont be + 一段时间+ before。 如95年6月就有对此的考查： Scientists say it may be five or ten years ____ it is possible to test this medicine on human patients