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.）