What does “When pigs fly” mean?
Used to say that something is impossible or extremely unlikely to happen.
Main example sentence
“He promises he will arrive early next time, but I told him, 'When pigs fly.'”
How and when to use it
The phrase often answers a prediction, promise, or request that the speaker does not believe. It can be playful among friends, but it may also sound sarcastic or dismissive. Avoid it when someone is sharing a serious ambition or concern unless that teasing tone is clearly welcome.
More natural examples
- He says he will organize the garage this weekend—when pigs fly.
- I will lend you my new guitar when pigs fly!
- Will our cat start enjoying baths? Yes, when pigs fly.
- They joked that the old rivals would cooperate when pigs fly.
Humor with a sarcastic edge
The expression can make disbelief entertaining, but it also rejects the idea very strongly. Facial expression and relationship determine whether it sounds playful or rude.
An intentionally impossible image
Ordinary pigs do not fly, so the imagined event represents a condition the speaker expects never to be met.