Definition
Used to emphasize that something will never happen.
指某事絕不可能發生。
He promised to give us a raise after the company layoffs, which will happen when hell freezes over.
他承諾在公司裁員後給我們加薪，這永遠不會發生。
You say he'll be on time? That will happen when hell freezes over!
你說他會準時？那永遠不會發生！
I will never forgive him, that'll happen when hell freezes over.
我永遠不會原諒他，那永遠不會發生。