Season seven of HBO's blazingly popular Game of Thrones series is set to debut this Sunday, and Duolingo, the language-learning app, is helping extremely dedicated fans to better appreciate the show's subtleties by offering lessons in High Valyrian. To be clear, High Valyrian is a fictional language invented specifically for the Game of Thrones series, and it's spoken by Daenerys, one of the leads.
Though High Valyrian is a fictional language, it is still real in the sense of having concrete grammatical rules and an extensive dictionary. The language was designed by David J. Peterson, a language specialist who has worked on several Game of Thrones languages as well as fictional languages for several other series. Peterson also collaborated on a university course about building fictional languages.