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课件网) 语法讲解 时间状语从句 一、时间状语从句的定义 用表示时间的连词连接一个句子作状语，这 样的主从复合句就是时间状语从句。连接时 间状语从句的连接词有:when, before, after, while, as soon as, until,since...... 这里要注意一点的是，如果主句是一般将来 时，从句只能用一般现在时表示将来意义。 今天初学，只讲解when、before、after 的用法。 二、时间状语从句-从属连词 引导时间状语从句的普通类从属连词有 when(当……时)，before(在……之前)， after(在……之后) 三、时间状语从句结构 1.主句+when/before/after+从句 2.=When/Before/After +从句，主句 翻译时先从句，再主句。 1.When引导的从句 译为当…时 (1)当我朋友来时，我正要外出。 I am going out when my friend comes. = When my friend comes, I am going out . (2)当他到家时，他的妈妈正在做饭。 His mother is cooking when he gets home. = When he gets home, his mother is cooking. 2.before和after 引导的从句 before译为在…之前；after译为在…之后 (1)上课前请把书准备好。 Please get your books ready before class begins. =Before class begins, please get your books ready. (2)我来这前不会英语。 I don’t know any English before I come here. (3)下完雨后我去看电影了。 After it rains, I go to the cinema. (4)放学后，我经常和朋友们打篮球。 I often play basketball with my friends after school is over. ※时间状语从句的时态 从句时态为一般现在时，主句时态为一般现在时、 现在进行时、祈使句、一般将来时。 练习一下吧! 1.I am watching TV when my sister comes back. are you when your sister back? 2.He has breakfast before he goes to school.(否定句) He breakfast before he to school. What doing comes doesn’t have goes 3.After he runs, he goes on the Internet. (一般疑问句) he on the Internet after he ? 4.She goes to Beijing after she leaves Shanghai. she to Beijing? Does go runs When does go 注意：时间状语从句在句型转换的时候， 变主句，从句不变。 when、before、after除了连词词性外，还有 介词词性。 (1)I hear him singing when coming in his room. = I hear him singing when I come in his room. (2)We go to a concert after having dinner. =We go to a concert after we have dinner. (3)He has some milk before sleeping. =He has some milk before he sleeps. 相互转化的原则：主从句主语一致，同时要注意从 句时态的变化。 Thanks a lot! Goodbye~
