was done和had been done的区别

Question

今天学习新二第34课。主要讲的被动语态的过去式和过去完成时的被动语态。
前面的比如he has been worried.he was wanted by the police.这些我都能弄懂。
但是后面他这讲他单车这里我没弄明白。
his bicycle had been found这句话。为什么要用过去完成？
如果用his bicycle was been found不就行了吗？
是不是因为找到这辆单车在警官和他说话之前。所以是过去的过去，用过去完成？
请老师详解，别忽悠。要详解！谢谢。

Answer 1

请各位大仙帮忙解释下以及语法
His trousers was been worn out.
他的裤子已经穿破了。
The bicycle is been riding by my brother now.
自行车给弟弟骑走了。
请仔细看看这两个例子！

Answer 2

his bicycle had been found这句话。为什么要用过去完成？
因为再过去之前就被发现了。

如果用his bicycle was been found不就行了吗？
这种用法是错误的。只可能是his bicycle has been found追问

为什么是错的呢？那为什么it is being sent又成立呢？

本回答被提问者采纳

Answer 3

对，就是这个意思，有个过去式作基准，自行车被发现发生在基准的过去，不就是过去完成时