过去将来完成进行时表动作从过去某一时间开始一直延续到过去将来某一时间。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。
1.should/would have been + v-ing构成；
如：I heard by July you’d have been teaching here for ten years.
我听说到七月份，你就在这里教了10年书了。
2.否定形式should/would+not have been + v-ing；
如：If I had known how he felt, I would never have let him adopt those children.
我要是知道他的想法，我是决不会让他领养那些孩子的。
3.疑问形式是将should/would提前。
4.过去将来完成进行时的情态意义
“would have been+现在分词”结构除用于表示过去将来完成进行时外，有时其中的 would 也可能是情态动词，具有情态意义，比较表示推测或猜想等。
如：“What interesting job have you found?” Helen asked him.
你找到什么有趣的工作啦?”海伦向他问道。
