have+been是什么时态

Question

如题所述

Answer 1

have+been是现在完成时，have been 已经；
所以用现在完成时，结构是have+过去分词(done)had+done是过去完成时，表示在过去这个时间点以前什么事情已经完成了；
例如：
I had done my homework before I went bed yesterday.

扩展资料

　　We took it as read that he must have been a KGB agent

　　我们完全相信他曾经是一名克格勃特工。

　　There have been some problems but basically it's a good system.

　　虽然出现过一些问题，但这基本上仍不失为一个好系统。

　　His family have been a very positive influence on him.

　　他的`家庭对他有十分良好的影响。

　　There have been many changes in recent years.

　　近几年发生了许多变化。