过去将来完成进行时表示动作从过去某一时间开始一直延续到对于过去来说的将来某一时间，动作是否继续下去，由上下文决定。在英语时态中，“时“指动作发生的时间，”态“指动作的样子和状态。
过去将来完成进行时是由should/would have been + v-ing构成；否定形式should/would+not have been + v-ing；疑问形式是将should/would提前。过去将来完成进行时的被动态。基本形式：should/would have been being done.
被动语态例句如下：
1.She said that by the end of last weekend, the book would have been being read for 2 weeks.
她说直到上周末，这本书就已经被读了两周了。
2.This topic would have been being considered for a month.
这个话题已经被考虑了1个月了。
3.Tom's room would have been being cleaned.
汤姆的房间会被打扫。
4.The play would have been being performed for 2 hours.
这场表演会持续两小时。
5.Up to that time those books had been being translated.
直到那时，这些书还在被翻译。
基本形式转换为被动态需要注意的是被动态的形式为should/would have been being done。不要和过去将来完成时的被动态would + have + been + done混淆。前者为持续性动作，而后者并无持续性的意思。
