鉴于英语语法的重要性，本文从动词(时态,语态,用法,省略,一致性等)整理了大学英语四级语法基础知识，希望大家可以认真阅读以下内容!
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.
3)将来完成进行时: 将来某个时刻以前一直在进行的动作.
By next summer, he will have been working here for twenty years.
In another month’s time she’ll have been studying here for three years.
4)将来完成时(由shall/will have + 过去分词构成): 将来某时已发生的事.
I shall have finished this one before lunch.
They’ll have hit the year’s target by the end of October.
语态
可以有两种被动结构的类型,例如:
He was said to be jealous of her success.
It was said that he was jealous of her success.
能同时适用于上述两个句型的主动词通常都是表示“估计”,“相信”等意义的动词,常见的有assume,believe,expect,fear,feel,know,presume,report,say,suppose,understand等.
It is supposed that the ship has been sunk.
The ship is supposed to have been sunk.
担当be supposed to 与不定式的一般形式搭配时往往表示不同的意义.例如:
Why are you driving so fast in this area? You are supposed to know the speed to know the speed limit. (你应该晓得速度限制)