内容正文:
Unit 2 Great People
单元语法复习
2021--2022学年第一学期期末考试英语复习
1
before, after, as 引导的时间状语从句
before 引导时间状语从句,意为“在……之前”,所表示的动作发生在主句动作之后。
主句和从句的时态:
(1)如果强调主句的动作发生在前,主句用过去完成时,before 引导的从句用一般过去时。
e.g. She had studied English for six years before she went to college. 在她上大学之前,她已经学了六年英语。
(2)如果不强调动作的先后,主句用一般过去时, before 引导的从句用一般过去时。
e.g. He worked in Shanghai before he came here.
在来这里之前,他在上海工作。
(3)如果主句是一般将来时,before 引导的从句用一般现在时。
e.g. It won’t be long before we meet again.
不久我们就会再见面。
—Did you catch the first bus to school this morning?
—No, I didn’t. It had started moving ______ I could get on it.
A. after B. since
C. before D. as soon as
C
主句和从句的位置:通常,时间状语从句位于主句前后均可。从句在前时,主从句之间必须用逗号隔开。
e.g. I’ll do it now before I forget it.
=Before I forget it, I’ll do it now.
趁还没有忘记,我这就把事情办了。
拓展:before 还可作副词,意为“从前,过去”。
e.g. I think we’ve met before. 我觉得我们以前见过面。
after 引导时间状语从句,after 意为“在……之后”,所表示的动作发生在主句动作之前。主句和从句的时态分别为:
如果强调从句的动作发生在前,主句用一般过去时,after 引导的从句用过去完成时。
e.g. After she had w