状语从句 本质——用不同的连接词将主句与一个或几个分句连接起来，以表达主句与分句之间的逻辑关系。 时间、地点、原因、目的、结果、条件、让步、比较、方式 时间状语从句 用来说明主句动作与从句动作发生时间上的先后关系 类型 常用连接词 特殊连接词 重点 时间 状语 从句 when, while, as, before, after, since, till, until, as soon as 名词：the moment, the instant, the minute, the day, next time, everytime 副词：instantly, immediately, directly 连词：no sooner„than, Hardly„when, scarcely„when 主句从句的时态搭配， 延续性动词与非延续性动词的区别 1. when 引导的时间状语从句可以理解为“当„„的时候” 辨析 The performer will already have played the music when we get there. The performer will be playing the music when we get there. 是否可以用 while 来替换? It is challenging for a company to remain inter-nationally competitive while the global economics are receding. 主句 分句 连接词 逻辑关系 时 态 搭 配 主从句都是过去时 态 主从句都用现在时 态 主句将来时 态 从句现在时 态 ※when, while, as 用法的区别 when 相当于 at that time，引导的状语从句中谓语动词可以是延续性的也可以是非延续性的 while，as 相当于 during that time, 引导的状语从句中谓语动词通常是延续性的 随着英特网变得日益商业化，网络的使用对商人们非常有利。 As the Internet becomes more and more commercialized, it is in the interest of business to universalize access. 公司很难在经济衰退的环境下保持自身的国际竞争力。 It is challenging that commercial organizations remain globally competitive, while the economics is receding. 2. before, after 引导的时间状语从句 before 可理解为在„„之前，after 可理解为在„„之后 主从句时态可明显体现动作的先后顺序 We should do everything for what we want before it is getting too late. He had never gambled before the casino sent him a coupon for 20 dollars worth of gambling. 3. since，until 引导的时间状语从句 （1）...
