For Star Trek fans, the final frontier doesn’t end once the credits roll on a new TV show or movie. The franchise extends way beyond that to include countless conventions, board games, video games, mountains of merchandise, and even a dating website specifically for Trekkies. And if you’re a real die-hard for Gene Roddenberry’s vision of the future, you can even learn Klingon—one of many fictional languages from the franchise, and by far its most fully-realized.

Now, the popular language-learning website Duolingo is helping people master the guttural beauty of Klingon with a free online course that is currently in a public beta. To start, you can choose to either learn some useful phrases or take an online placement test—though that’s recommended for people who already have some experience in Klingon. The course was crafted with the help of CBS—both Trek and the network are owned by Viacom—as well as “some of the world’s leading Klingon experts,” according to a quote from VentureBeat.

If you’re a novice, Duolingo will start you off with some tips on how the Klingon language works, including its alphabet, capitalization rules, and the fact that there’s really no word for “hello” (apparently, a Klingon won’t waste your time with silly trivialities like greetings).

In an interview with VentureBeat, course creator Felix Malmenbeck said there are only about 30 to 50 people who can actually converse in Klingon, though there are more who can communicate through text. But there’s a chance that number can shoot up with this new course, as Malmenbeck revealed that the site has gotten around 170,000 pre-registrations. This might seem like a lot for a fictional language, but just remember that the site’s course for High Valyrian, a fictional language from Game of Thrones, was viewed by 240,000 eager learners.

Klingon made its debut as a very basic language in 1979's Star Trek: The Motion Picture and was partly devised by actor James Doohan, who played Scotty. It was further fleshed out in 1984's Star Trek III: The Search for Spock, and it has since gotten its own dictionary by the linguist Marc Okrand, the man responsible for working on the official language for the movie.

Duolingo’s Klingon course is available now for free, and if you have a Duolingo Plus subscription, you can experience the whole thing without ads and use it while offline. Just remember, be careful who you say hab sosli' Quch* to. It may not end well. 

*It means “Your mother has a smooth forehead.” Trust us, that’s as insulting as it gets.

[h/t VentureBeat]