在非真实条件句中，表示与过去事实相反的假设。

If I had known the truth, I would not have said that to him.

youdao

要不是的帮助，我就不能提前完成这项任务。(与过去事实相反的虚拟条件句)。

If it hadn't been for your help, I couldn't have finished it ahead of time.

youdao

要不是那个会议，我就参加了你上周六举行的晚会了。(句中动作与过去事实相反)。

If it hadn't been for the meeting, I would have gone to your party last Saturday.

youdao

And the truth of the matter is,when my body dies,that's all history.

而事实是，我肉体死亡时，一切都成过去了。

耶鲁公开课 - 死亡课程节选