I've never had such a linguistic double take after hearing a colleague, who grew up in France, tell me that Nike's or Adidas' billboards in France say: "Le leader en sportswear", pronounced as if it contained four French words (lee-dayr, spôrt-swear, stress on the final syllable in both cases).
In Russian the word for train is poezd, and the prepositional form is poezdje, so you say "I am on the train" "ya v poezdje" (Russian has no articles and drops the copula when it carries no information, so word for word it's "I on train.") One of my friends once told her mom on the phone "ya v trenje" meaning that she took the word "train," pronounced it as though it were a native Russian word "tren", and added the typical masculine inanimate prepositional ending to it. Kinda funny.