was doing、had been doing和had been done都有什么区别?

问题描述:

was doing、had been doing和had been done都有什么区别?
was doing和had been doing不是都是指过去一段时间做的事情吗?他们俩有什么区别吗?
had been doing 和 had been done 又有什么区别.

话说我在写英语句子时不知道什么时候该加ing...怎么办TAT

was doing是过去进行时,表示过去正在发生.例如:She was washing when her son came in.(她儿子进来时她正在洗衣服.)
had been doing是过去完成进行时,基本相当于过去完成时,但可以强调动作延续.例如:They had been playing chess for the whole afternoon when their father went back from work.(他们的父亲下班回来时,他们已经下了一下午棋了.)
had been done是过去完成时的被动式,和前两个没有关系.例如:When the firemen got to the building,the fire had been put out.(等消防员感到那栋大楼的时候,火已经被扑灭了.)