一、我们来分析过去将来完成时时态，可以看出，过去将来完成时有3种时态，第一个是表过去的动作，第二个表将来，第三个表完成，而过去将来有可表示为would/should do sth，完成时表示为have done，因此过去将来完成时就可表示为：would/should have done.例如：
He told me he would have finished it by the end of the next month.
他告诉我他下个月结束时他将完成它。

二、过去将来完成时的被动语态结构：should have been done , would have been done.例如：
1.I believed by the end of that year an advanced version of that software would have been developed, but I was wrong.
我坚信到那年年底为止，那个软件的新版本将被开发出来。但是我错了。
2.He said that the garden shed would have been being cleaned for two hours by nine o’clock.
他说到九点为止花园的小棚子将已经被打扫了两个小时了。
3.It would have been completed before 8 o'clock.
它将会在八点之前被完成。
4.He said his work would have been finished by him the next day.
他说明天他将会完成他的工作。