French is full of colorful expressions, and “tomber sur un os” (literally “come across a bone”) is a perfect example. It describes those moments when you’re moving along smoothly with a task, and suddenly—something unexpected throws everything off track.
Where Does This Expression Come From?
The phrase comes from the world of butchery. When a butcher is cutting through meat, everything is going fine… until they hit a bone. The knife gets stuck, they have to work harder, and what seemed easy suddenly becomes a hassle. It’s a great metaphor for life’s little (or not-so-little) obstacles that catch us off guard.
A French Classic
This expression is commonly used in all sorts of situations, often with a hint of frustration:
🛠️ At work: “Je pensais finir ce dossier vite, mais je suis tombée sur un os avec ces fichiers corrompus.” → “I thought this report would be a breeze, but I hit a snag with those corrupted files.”
🚗 In everyday life: “On était prêts pour partir en vacances, mais on est tombés sur un os : plus de batterie dans la voiture !” → “We were all set for our trip, but then we hit a snag—our car wouldn’t start!”
📚 At school: “Tout allait bien pendant l’examen, puis je suis tombée sur un os… un exercice incompréhensible !” → “The test was going fine until I hit a snag… a question I had no idea how to answer!”
What About You? Have You Ever Come Across A Bone?
We’ve all had moments when something that seemed simple turned into a headache. Share your stories on my socials!
The sources I used to write this post are listed below:
Lille, Samantha. Le saviez-vous ? « Il est tombé sur un os » (2017). Site archives du ministère des Armées [online]. Retrieved from: https://archives.defense.gouv.fr/actualites/articles/le-saviez-vous-il-est-tombe-sur-un-os.html (02/28/25).
Rey, Alain, et Sophie Chantreau. Os. In Dictionnaire des expressions et locutions, Dictionnaires Le Robert, 2003, p. 663.