H. Beam Piper once wrote "Modern colloquial English is the end result of Norman men-at-arms trying to make dates with Saxon barmaids", and it's been promoting cross-cultural understanding ever since. It's a nightmare to learn, as it seems for every hard-and-fast grammatical rule there are at least a dozen exceptions, but it's also great for getting an explanation across when rules would get in the way. Then again, what other language takes slang acronyms for military profanity and codifies them as new words (snafu, fubar)?
