助动词have的用法

have

v.aux.
(过去式和过去分词为had [hAd]; 第三人称单数现在式为 has [hAz; hEz, Ez])
[构成各种完成形式]业已, 曾经
You haven't been abroad before, have you?
你以前没出过国, 是吧? ②[用于虚拟语气]
If they had [had they] time, they would certainly come and help us.
如果他们有时间, 他们一定会来帮助我们。

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。
http://edu.sina.com.cn/en/2005-02-01/30273.html

和动词过去分词连用，构成现在、过去完成时