过去完成进行时
1.概念
(1)表示到过去某个时刻此动作还在进行。
（2）用在从句中，从句的动作发生在主句的动作之前而对其有影响。
①At last the bus came, I had been waiting for half an hour.
②Until then she had been loving her daughter.
③Her eyes were red. It was obvious she had been crying.
④I heard you’d been looking for me.
wｗw.ExamＷ.CoM 2.基本结构
S+had+been+doing注意其否定、疑问形式。
3.现在完成进行时/过去完成进行时
He’s been smoking for 20 years.
He’s still smoking.
He’d been smoking for 20 years when he decided to give it up.
至过去某个时刻还在进行某动作。
4.过去完成时/过去完成进行时
By last week she had collected 2000 stamps.(已完成)
She had been collecting stamps all these years.(未必完成)
She had been painting the door all afternoon.(未必完成)
