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。