过去将来完成时在英语语法时态中是不经常用到的一种时态，因为它所表示的意思也是人们不经常发生的状态，过去将来完成时可以用在虚拟语气中，表示与过去的事实相反。若表示与过去事实相反的虚拟语气，此时条件从句的谓语用过去完成时(had+过去分词)，而主句谓语则通常用过去完成时（would+have+过去分词），当然，主句谓语也可根据情况使用“should (could, might)+have+过去分词”。例如：
1. If I'd left sooner, I'd have been on time.
要是我早点动身，我就准时到了。(但我动身太迟了)
2. If we had found him earlier we could have saved his life.
要是我们当时早点找到他的话，我们就可以救活他。(可惜我们找到他太晚了)
3. If I had known that you were coming I would have met you at the air-port.
要是我早知道你要来的话，我就会在机场接你了。
4. If he had lived, some day Michael would have done something important.
假定麦克尔当时在世的话，他本可做出了不起的事。
5. 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。
6. He would have forgotten the boy’s birthday if you hadn’t reminded him.
要不是你提醒他，他会忘记这男孩的生日的。
7. Our lives would have been greatly impoverished if we had not known our dear friend.
若不是得识我们这位好朋友，我们的生活一定十分不妙。
8. If we had come earlier we could have got on the bus.
要是我们当时早点来的话，我们就可以坐上公交车了。
9. If I had known how he felt, I would never have let him go to France.
我要是知道他的想法，我是决不会让他去法国的。
10. He would have missed this party if you hadn’t reminded him.
要不是你提醒他，他会错过这次聚会。