大学英语四级语法精要 大学英语四级语法精要

大学英语四级语法精要

Ⅰ动词(时态,语态,用法,省略,一致性等)

1.   时态

1)现在完成进行时态 (have/has been + -ing 分词构成): 动作或状态从过去某时开始,继续到现在,可能继续下去,也可能刚刚结束.

I’ve been writing letters for an hour.

I’ve been sitting in the garden.

2)过去完成进行时(由had been + ing分词构成): 过去某个时刻以前一直在进行的动作

I’d been working for some time when he called.

We had been waiting for her for two hours by the time she came.