被动语态是相对于主动语态而存在的。英语中就这两种相反的语态。主动语态表达的是主语是谓语动词的发出者。相反，被动语态表达的是主语是谓语动词的承受者。例如:主动语态:I invited Lijun to my birthday party yesterday.被动语态:Lijun was invited to my birthday party yesterday.
过去完成时是属于动词的时态系列，表示“过去的过去”。例如:My sister had lived here for five years before I came here.
可以看出它们的结构有相同之处，就是动词都是过去分词;也有不同之处，就是助动词一个是be （过去时是were,was)，一个是had。
