Somebody write this

Speculative fiction writers. In this culture, whenever anybody speaks more than a very brief phrase -- more than three words, let's say -- they end their statement with an extra word. This word stands outside the ordinary grammar of the statement. Whoever answers is bound by deep cultural logic to weave this extra word into their answer. If they were to omit the word, then to the ears of this people, they wouldn't even have made speech, just babble.