16 过去将来完成进行时 would have been + 现在分词
过去将来完成进行时表示从过去某一时间来看，到将来某一时刻之前一直在持续进行的动作，并且该动作可能还会继续下去。
一、构成
would have been + 现在分词
二、用法
1. 从过去的视角描述将来某一时刻之前的持续动作。
例如：She said she would have been waiting for him for two hours by six o'clock.（她说到六点钟的时候她就会已经等他两个小时了。）这里是从过去“她说”的时候看，到将来的“六点钟”这个时刻之前，“等待”这个动作一直在持续进行，并且可能在那之后还会继续。
He thought he would have been working on that project for a week by the end of next month.（他觉得到下个月底的时候他就会已经在那个项目上工作一周了。）
三、句式变化
1. 否定句：在 would have been 后加 not。
例如：I thought I would not have been studying so hard by this time tomorrow.（我原以为到明天这个时候我不会一直在这么努力地学习。）
2. 一般疑问句：将 would 提到句首。
例如：Would you have been waiting for a long time by the time he arrived?（到他到达的时候你会已经等了很久了吗？）
3. 特殊疑问句：特殊疑问词 + would + 主语 + have been + 现在分词 + …?
例如：How long would they have been traveling by the end of next year?（到明年年底他们会已经旅行了多久？）
