1)have +過去分詞，構(gòu)成完成時(shí)態(tài)，例如：

He has left for London.他已去了倫敦。

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

上月未為止，他們已經(jīng)完成工作的一半。

2)have + been +現(xiàn)在分詞，構(gòu)成完成進(jìn)行時(shí)，例如：

I have been studying English for ten years.

我一直在學(xué)英語，已達(dá)十年之久。

3)have+been +過去分詞，構(gòu)成完成式被動(dòng)語態(tài)，例如：

English has been taught in China for many years.

中國教英語已經(jīng)多年。