1）have +过去分词，构成完成时态。

例如：

He has left for London.

他已去了伦敦。

By the end of last month, they had finished half of their work.

上月未为止，他们已经完成工作的一半。

2）have + been +现在分词，构成完成进行时。

例如：

I have been studying English for ten years.

我一直在学英语，已达十年之久。

3）have+been +过去分词，构成完成式被动语态。

例如：

English has been taught in China for many years.

中国教英语已经多年。