内容正文:
模块语法小专题
语法精讲
状语从句(Ⅰ)
时间状语从句
在复合句中起时间状语作用的句子称为时间状语从句。在此主要学习由while,when,as,before,after,as soon as,until,since引导的时间状语从句。其具体用法如下:
1.when,while,as引导的时间状语从句
从属连词when,while,as 都可引导时间状语从句,意为“当……时候”;但用法上又有所不同。
(1)when用法最广,常可代替while 与as。与while相比,when 引导的从句中动词既可以是延续性的,也可以是短暂性的。as在这一点上与when 相同,while 所引导的从句中,动词只能是延续性的。如:
The telephone rang while I was taking a bath.我在洗澡时电话响了。
(2)当两个表示时间延续的动词同时发生而又具有对比意味时用while,在这样的复合句中,主从句的时态通常是相同的。如:
My father was preparing a report while I was playing computer games.我玩电子游戏的时候我爸爸正在准备报告。
(3)表示两个发展变化中的情况时常用as。如:
As you grow older,you'll know better and better about yourself.随着你慢慢长大,你会对自己越来越了解。
(4)表示“一边……一边……”时,用as。如:
The girl said hello to me as she was walking.那个女孩一边行走一边向我问好。
(5)表示随着短暂动作的发生,另一行为伴随发生,这时常用as。如:[来源:学科网]
My cap was blown away as I stood up.当我起立的时候帽子被吹走了。
2.before与after引导的时间状语从句
before意为“在……之前”,引导的时间状语从句表示主句的动作发生在从句动作之前;after意为“在……之后”,引导的时间状语从句表示主句的动作发生在从句动作之后。如:[来源:Z*xx*k.Com]
We cleaned the classroom before we left school yesterday.昨天我们离校之前打扫了教室。
He called me after he finished his homework.他完成作业之后给我打了电话。[来源:学科网ZXXK]
3.as soon as引导的时间状语从句
as soon as意为“一……就……”,引导的时间状语从句中主句为一般将来时时,从句要用一般现在时。如:
I will call you as soon as I arrive in Beijing.我一到达北京就给你打电话。
4.until引导时间状语从句
until意为“直到……”,引导的时间状语从句中主从句都是肯定句,主句的谓语动词为持续性动词时,until相当于till。not…until 意为“直到……才……”,主句的谓语动词一般为非持续性动词。
5.since 引导的时间状语从句
since意为“自从……以来”,其引导时间状语从句的用法主要有两种:
(1)主句(现在完成时)+since时间状语从句(一般过去时)。如:
He hasn't been home since he graduated.他毕业后没回过家。
(2)It be+一段时间+since时间状语从句。如:
It is two years since I became a postgraduate student.我成为研究生已经有两年了。语法精练
Ⅰ.用适当的表示时间的从属连词填空。
1.When the fire took place,all the students were sleeping.
2.My brother was preparing a report while I was reading.
3.I didn't know English before I came here.
4. After he locked the door,he left.
5.I'll come to see you as__soon__as I arrive there.
6.They worked until/till it was dark.
7.I didn't go to bed until my father came back.
8.Be quiet while/when I was writing a letter.
9.I'll return the book as__soon__as