过去分词的用法

过去分词一般要和其它成分连用：①have has +过去分词 （现在完成时）、②had+过去分词（过去完成时）、③be+过去分词（被动语态） 。具体例子如下：

during the 1980s,revoluntionry changes in the work lives of Americans,caused by technological advance which will permit greater productivity by fewer workers,will likely result in shortened work weeks,increased released time for workers,and increased pressure for early retirements.

revoluntionry changes 是主语中心词,caused by.是过去分词修饰主语．（其前没有助动词,这是判断是否是过去分词或过去式的一个重要的标志．所以很容易看出它不作谓语．） 。

will likely result in 是谓语 。

shortened work weeks 是宾语1 increased released time 是宾语2 increased pressure 是宾语3 这些~ed分词都是作形容词用．很容易理解。