That will only happen "When pigs fly"...
The phrase ‘When Pigs Fly’ refers to something that is highly unlikely to ever happen/something that will never happen/impossible
Similar idiom: when hell freezes over
Most commonly used in Canada and the US.
Examples:
“I might wake up early tomorrow to clean my room”. “Yes, you’ll do that 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.
“I think I’ll start working on my project from tomorrow.” “Yes, and pigs might fly.”
“Do you think our team will win the competition?” “Yes, flying pig.”
John asked Sarah whether she would go to the movies with him, Sarah replied that would happen when pigs fly.
He plans to clean his house every week, but he will probably do it only when pigs fly.
“Someday, I’ll become a successful actor.” “And pigs might fly.”
I’ll join your physics classes when pigs fly.
Interesting fact
There have been many mentions of flying pigs throughout history, and there’s some argument about the origin of the idiom “when pigs fly.” The most general consensus is that the term originated either in Germany or Scotland, as there are plenty of examples of its use as a way to describe something that is physically impossible.
Other Language Idioms Equivalent to When Pigs Fly
Arabic (Algeria) - when salt blossoms in my country
Chinese - Unless the sun would rise from the West
English - When hell freezes over
- On a cold day in hell
- Not in a month of Sundays
French - When chicken have teeth
German - When Hell freezes over
- When it snows in summer
Italian - In the week with two Thursdays - When donkeys will fly
Polish - on Saint Never's Day
Portuguese - When the cow coughs
- On Saint Never's day
Russian - When the crayfish on the hill whistles
Spanish - When frogs grow hair