when pigs fly



يستخدم للتعبير عن شيء من المستحيل حدوثه.

أمثلة:

he'll pay for the drinks-when pigs fly.

Her crazy mother said that being so lazy, Megan is going to be rich one day for sure and without any hard working job. Come on, when pigs fly!

I asked my boss if I could go on a two-month vacation, he said yes, when pigs fly!

I think he’ll pay you back your money – when pigs fly.
Source: theidioms.com