For many, learning a new language is a great way to simultaneously engage your brain and feel productive. Whether you want to learn Spanish for everyday use or French for an upcoming European vacation, tools like Rosetta Stone and Fluenz are effective ways to teach yourself a language much faster than a community college class would, for example.

Today, there are lots of mobile apps dedicated to teaching you any language your heart desires. Duolingo, one of the most prominent, offers more than 20 different languages, taught to users via a series of game-like quizzes — all (well, mostly) for free! Just in time for the season 7 premiere of Game of Thrones, the Duolingo team revealed its latest course: High Valyrian.

For those unfamiliar with Game of Thrones (or, as it were, George R.R. Martin’s A Song of Ice And Fire book series, where the language appears more frequently), Valyrian is the language spoken by the Targaryen family, descendants of Old Valyria — a bygone empire once known as the most powerful in the fictional world, located in Essos, southeast of the Free Cities. In its heyday, the Valyrian Freehold was home to the Dragonlords, a collection of noble families in possession (and control) of dragons.

In the television series, Valyria is nothing more than a distant memory — a ruined empire seen by Tyrion Lannister and Jorah Mormont during their voyage in season 5. The only remaining Targaryen and the only character who speaks Valyrian in the show is Daenerys Stormborn (First of her name, the Unburnt, et cetera), although several characters in Essos speak different dialects of the language in earlier seasons.

The language, which spent several months in Duolingo’s Incubator, was created by David J. Petersen, who is known for his work developing fictional languages and teaching courses on them. Peterson provided updates via the Incubator under the pseudonym Valyrio Māzitas, which translates to “Valyrian is coming.” As Valyrian is spoken sparely by characters in the series, Petersen constructed the language largely around the phrases “Valar Morghulis” and “Valar Dohaeris”, which translate to “All men must die” and “All men must serve,” respectively.

He is also largely responsible for developing the Dothraki language spoken in the show. If you would like to learn Dothraki, Living Language offers a course. The Duolingo course for High Valyrian is available now, but it’s technically in a beta phase, so it is possible that there are some hiccups or errors. To download Duolingo for free, head to the iOS App Store or the Google Play Store.