when、as、while引导的时间状语从句.ppt

when、 as、 while引导的时间状语从句,1. when、 as、 while引导的时间状语从句分析： (1) when引导时间状语从句时表示“当的时候”， when既可以指时间段也可指时间点， 从句中既可用延续性动词又可用非延续性动词， 且动作既可和主句的动作同时发生又可在主句的动作之前或之后发生， 注意体会如下例句： Ill call you when I get there. 我一到那里就给你打电话。,(2) while引导时间状语从句时表示“当的时候”， 它强调主句的动作与从句的动作同时持续地进行， 用于这一用法时while引导的时间状语从句和主句中的谓语动词必须是延续性动词 (3) as引导时间状语从句时表示“当时， 一边一边”， 侧重表示两个动作同时发生(包括一个主语同时进行两个动作)， 或者一种动作随着另一种动作的变化而变化。例如： He jumps as he goes along. 他边走边跳。,1. We were swimming in the lake _ suddenly the storm started. (2004北京春) A. when B. while C. until D. before 2.考题5 _ the days went on, the weather got worse. (1990) A. With B. Since C. While D. As,A,答案 D 解析 表示“the days went on”、 “the weather got worse”两个相互伴随地进行变化的动作， 应选as表示这一时间关系 While用法小结 一、while作名词用，表示“一会儿”“一段时间” 1.She likes to lie down for a while after lunch. 她喜欢午饭后躺一会儿。 2.Coming to another country to study requires a big adjustment and it takes a while to fit in. 来到另一个国家求学，需要花一段时间来适应。,二、While作连词 (1)引导时间状语 1.We must strike while the iron is hot.趁热打铁。 2.While she was listening to the radio，she fell asleep. 她听着收音机睡着了。 (2)引起让步状语从句，意思是“虽然但是.”、“尽管但是”(多放于句首)1.While he loves his students，he is very strict with them 虽然他爱他的学生，可是他对他们很严格。,三、While作并列连词用，意思为“而，然而”，表对比。而but表转折。注意用心比较体会while与but的句中用意 1.Some people waste food while others havent enough. 有些人很费粮食，然而有些人却吃不饱。 2.The son was having a good meal at home，while the parents were working in the fields. 儿子在家吃好饭而父母却在田里辛勤劳作。 3.I ought to have helped her，but I never could. 我本该帮她但没能。,二.选择最佳答案： 1.She thought I was praising her child，_，in fact，I was scolding him for his bad behaviors at school. A.what B.while C.so that D.therefore 2.I do every single bit of housework _ my husband Bob just does the dishes now and then.(2004全国卷II35) A.while B.since C.when D.as 3._ it is expected that students come university with the ability to take a good set of notes，this is not always the case. A.When B.As C.For D.While,4.We were swimming in the lake _ suddenly the storm started. A.when B.while C.until D.before 5.-You seem to have had that car for years. -Yes，its in good condition，but I should sell it _ it still runs. A.if B.before C.because D.while 二.1.选