过去将来完成进行时的被动态

过去将来完成进行时，表示动作从过去某时间开始一直延续到对于过去来说的将来的某一个时间。基本形式：should/would have been doing。虽然不是个常用时态，我们也要认识认识它~今天要介绍的是过去将来完成进行时的被动态。基本形式：should/would have been being done.

请看例句：

1. He said the trees would have been being planted on March 12th on the mountain this year by the students, because the school had already decided. 他说今年3月12日会有很多树苗被学生种下，因为学校已经决定这项活动了。

2. 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。

3. This topic would have been being considered for a month. 这个话题已经被考虑了1个月了。

4. Tom's room would have been being cleaned. 汤姆的房间会被打扫。

5. The play would have been being performed for 2 hours. 这场表演会持续两小时。

6. Up to that time those books had been being translated. 直到那时，这些书还在被翻译。

7. The letter had been being written till two o'clock. 写这封信写到了2点。

由基本形式转换为被动态还是挺简单的，不过这里需要注意的是被动态的形式为should/would have been being done。请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。