与过去的事实相反

If I had known his address, I would have written to him.假如我知道他的地址，我早就写信给他了。（事实上我当时并不知道他的地址，所以那时没给他写信。）

If I had had a bike, I would have lent it to you yesterday./ You would have been able to do very well if you had taken this quiz at the beginning of the course./ If I had arrived sooner, I would not have missed the show.

以上三句中，条件句表示的都是与事实相反：第一句表示“昨天我没有自行车”，第二句表示“你没有参加他的考试”，第三句则表示“我没有及时赶到”。所有这些表示与过去事实相反的假设，其假设句应用过去完成时。