I'll bet the French don't have a word for louvres.
Used to work with a guy called Christophe from Grenoble. Our favourite piece of office sport was to ask him "Hey Christophe, what's the French word for raison d'etre?' and other adopted French expressions. He would always fall for it and patiently explain that they were French words, whilst we would tell him they were in the English Dictionary so they could not be French and he must be mistaken...
