This French expression is likely to feel simultaneously familiar and strange to English-speakers.
Why do I need to know coûter un bras?
Because this expression is an interesting example of how the French and English languages have been influencing one another for centuries.
What does it mean?
Coûter un bras – roughly pronounced koo-tay uhn brah – translates as ‘to cost an arm’.
For English-speakers, this expression likely sounds familiar and also strange. It has the same meaning as the phrase ‘to cost an arm and a leg’ - which means that something is very expensive.
In fact, linguists believe that the French expression only dates back to the 20th century, and that it likely comes from the English expression - aside from the fact that the French seem to view an arm as sufficiently expensive in its own right.
As for the origins of the expression in English, experts have not settled on one explanation. The first theory argues that prior to the 20th century, full-body portraits (meaning those including arms and legs) were more expensive. Meanwhile, the second and more popular theory states that the phrase became popular following World War II, when people were known to say that the price of going to war was ‘an arm and a leg’.
In the 1940s, the expression became more popular when American advertisers began to describe things as ‘costing an arm and a leg’.
As for the French side, a different expression about the price of precious body parts has been popular since at least the 19th century: coûter les yeux de la tête.
These days, however, both phrases are commonly used.
Use it like this
J'ai pensé à acheter cette bague, mais elle coûte un bras. – I thought about buying that ring, but it costs an arm and a leg.
Il a décidé d'acheter la nouvelle voiture, même si elle coûte un bras. – He decided to buy the new car, even if it costs an arm and a leg.
