過去完成進行時
　　1.概念
　　(1)表示到過去某個時刻此動作還在進行。
　　（2）用在從句中，從句的動作發(fā)生在主句的動作之前而對其有影響。
　�、貯t last the bus came,  I had been waiting for half an hour.
　�、赨ntil then she had been loving her daughter.
　�、跦er eyes were red. It was obvious she had been crying.
　　④I heard you’d been looking for me.wｗw.ExamＷ.CoM
　　2.基本結(jié)構(gòu)
　　S+had+been+doing注意其否定、疑問形式。
　　3.現(xiàn)在完成進行時/過去完成進行時
　　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.
　　至過去某個時刻還在進行某動作。
　　4.過去完成時/過去完成進行時
　　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)