Language, Darwin believed, was not a conscious invention but a phenomenon “slowly and unconsciously developed by many steps.” But what makes a language a language? In this short animation from TED Ed, linguist John McWhorter, author of the indispensable The Power of Babel: A Natural History of Language (public library), explores the fascinating world of fantasy constructed languages — known as conlangs — from Game of Thrones’ Dothraki to Avatar’s Na’vi to Star Trek’s Klingon to Lord of the Rings’ Elvish. Though fictional, these conlangs reveal a great deal about the fundamentals of real human communication and help us understand the essential components of a successful language — extensive vocabulary, consistent grammar rules but peppered with exceptions, and just the right amount of room for messiness and evolution.