How do you say “When pigs fly” in French?
The closest natural French equivalent is Quand les poules auront des dents, which literally means “When hens will have teeth”. English speakers use when pigs fly to mean this expression means that an event will never happen because it is completely impossible. A very familiar humorous answer to an unlikely promise or possibility. It is informal and common in everyday French.
Closest natural French
Quand les poules auront des dents
/kɑ̃ le pul o.ʁɔ̃ de dɑ̃/
- Literal meaning
- “When hens will have teeth”
- Register
- informal
- How often it's used
- common
- Equivalence
Near-exact equivalent
97 out of 100
What a native French speaker would actually say
Both languages imagine farm animals doing something impossible. English pigs fly, while French hens grow teeth.
The humour and disbelief match closely. Use the phrase with care when someone expects a serious answer.
How close is the meaning?
- Meaning5 out of 5
- Tone5 out of 5
- Context5 out of 5
- Literal similarity2 out of 5
These ratings are editorial approximations, not measurements.
What are other ways to say it in French?
À la Saint-Glinglin
Literally: “On Saint Glinglin’s Day”
An imaginary date, often used about endless delays.
Tu peux toujours rêver
Literally: “You can always dream”
More direct and potentially sharper when rejecting a hope.
Don't translate it literally
Quand les cochons voleront
French normally gives hens teeth for this joke rather than making pigs fly.
Word-for-word versions like these are understood as literal statements in French, not as expressions.
In context
English
He’ll tidy his room when pigs fly.
French
Il rangera sa chambre quand les poules auront des dents.
English
They’ll pay us back when pigs fly.
French
Ils nous rembourseront à la Saint-Glinglin.
Related expressions
Last reviewed 2026-09-12