You've probably heard of blunders by Japanese businessmen in English, such as translating "hitotsu yoroshiku" as "one, please" instead of "I look forward to working with you." Less known, but no less common, are the slip-ups foreigners make in Japanese, especially when using that dreaded form of honorifics known as "keigo."
Appearing in texts as ancient as the "Kojiki" (712 AD), keigo is a fundamental part of Japanese, said to be as old as the language itself. While other languages have honorifics, such as "tu" and "vous" in French, keigo transforms virtually every aspect of a sentence and implies a distance and hierarchy between people who speak it.
There are five official forms of keigo — "sonkeigo" (honorific language to elevate someone), "kenjogo" (humble language to lower yourself), "teineigo" (polite language ending in "desu" or "masu"), "teichogo" (a form of humble language that doesn't require the speaker to be on the receiving end of an action), and "bikago" (beautifying language, when "o" or "go" is put in front of a noun). All of these are used differently depending on the situation. The crazy uncle in the keigo family is "baito keigo," a form of keigo spoken in convenience stores and restaurants that ignores the conventions of normal speech (e.g. "Udon ni narimasu," which translates as "This will become udon").