The French are known to be very chic… and it’s no surprise they have an expression for it.
Why do I need to know se mettre sur son trente-et-un?
This French expression is good to know if you’re going to a party, especially around New Year’s Eve…
What does it mean?
The expression se mettre sur son trente-et-un, roughly pronounced suh metr sur sohn trahnt-ay uhn (listen here), literally translates to “to put yourself on your thirty-one”.
In reality, it means “to dress up elegantly” or “to put on your best clothes”. It can also be spelt with the number – se mettre sur son 31.
Its English equivalent would be “dressed up the nines”, which also uses a mysterious number for elegance.
The expression is often associated with New Year’s Eve, which falls on December 31st. On that day, it is common for people to dress up when attending a party to celebrate the New Year.
But this expression dates back to the Middle Ages and is actually derived from the old French word trentain, which referred to a luxurious cloth or a fine fabric worn only by the very wealthy. Over time, trentain is said to have become trente-et-un (31).
As for the phrase se mettre sur, it is thought to be an old way of saying mettre sur soi (to put on oneself), “to dress”.
The expression today is well known for describing elegance.
Use it like this
Pour le mariage, tout le monde s’est mis sur son trente-et-un. – For the wedding, everyone dressed up to the nines.
N’oublie pas de te mettre sur ton trente-et-un ce soir, nous fêtons l’anniversaire de ton père. – Don’t forget to dress up tonight, we are celebrating your dad’s birthday.
Je vais me mettre sur mon 31 pour la soirée du nouvel an. – I will wear my best clothes for the New Year’s Eve party.
