If you're planning a jaunt into French-speaking territory, you're bound to encounter communication problems at one point or other.
Since you're reading this, you're obviously taking measures to ensure you don't end up standing in the middle of a room bellowing "DOES ANYONE SPEAK ENGLISH?"... but even so it's good to know a few phrases so that if accents are too thick, speech is too fast, or vocabulary is too obscure, you can politely say "sorry, I don't understand."
Then stand in the middle of the room and bellow "Y a-t-il quelqu'un qui parle anglais?"