Gone are the days when you could have a show about a fantasy world where characters spout random, made-up gibberish as their "language." When you put a lot of thought into the costumes, weaponry, and hair styles of your invented culture, you had better give it a proper language too. That way motivated fans—and there will be fans this motivated—can figure out the system to it and even learn to speak it themselves. The producers of Game of Thrones did the smart thing when they hired language creator David Peterson to work out realistic languages for the show. Here are seven cool facts about the language from the first two seasons, Dothraki.

1. Peterson got the job to create Dothraki by winning a contest among language inventors.

The Language Creation Society was founded in 2007 as an organization where people who invent languages as an artistic and intellectual hobby (known as "conlangers" from "constructed language") could share their work and promote their craft. When producers approached them asking for help creating Dothraki, the society held an internal contest and selected Peterson's 180-page proposal (along with dictionary and audio files) to present to the producers, who hired him.

2. A lot of what's in the vocabulary and grammar of Dothraki has never appeared on the show.

With Peterson's dictionary of over 3000 words, and his description of the proper way to form a wide range of sentence types, you could say all kind of things in correct Dothraki that have never been uttered on the show. Want to compose some wedding vows? Write a poem? Translate Shakespeare? Learn Dothraki and give it a go!

3. One grammatical feature was inspired by Dwight Schrute.

Last fall NBC aired an episode of The Office where Dwight tries to convince Erin to learn Dothraki instead of French. The writers did their homework and (without consulting Peterson) managed to use valid Dothraki. They even extended the grammar in an interesting way. Peterson had not yet explicitly described how noun-verb compounds work, but he noticed the Dothraki compound examples Dwight has written on a piece of paper—foth aggendak (I throat-rip), foth aggendi (you throat-rip), foth aggenda (he/she/it throat-rips)—and decided to deem it good Dothraki. That construction is now known as a "Schrutean compound."

4. Peterson's wife and cat are lovingly honored in the vocabulary.

In a sweet gesture, Peterson's took his wife's name, Erin, and turned it into the Dothraki adjective meaning kind or good, from which is derived the verb "erinat" (to be good) and the noun "erinak" (lady, kind one). The word "okeo" is a tribute to a beloved cat, adopted by Peterson and his wife while he was beginning to work on the language. At the shelter the cat's name was "Oreo" but the way it was written on his tag made it look like "Okeo," so that's what they called him. Okeo died at 7 months from a congenital liver problem, but his name lives on as the Dothraki word for "friend."

5. If the actors ad-lib any Dothraki, it has to be retrofitted to the grammar.

The last Dothraki line of season 2 was ad-libbed by Iain Glen, who plays Jorah. In some bit of last minute shooting, the producers had sent Peterson an emergency request for a translation of "take all the gold and jewels," but the translation he provided didn't make it in time, so Glen improvised something. Later Peterson took the ad-libbed line, and figured out a way to make it proper Dothraki by deriving a couple of new words and assuming some minor mistakes on the part of Jorah (who is not a native Dothraki speaker). He managed to plausibly get the improvised line to mean "the loose valuables are for loading," which fit both the language and the situation perfectly.

6. Dothraki has tongue-twisters.

Qafak qov kaffe qif qiya fini kaf faggies fakaya.

Say it three times fast. It means "the trembling questioner crushed the bleeding boar that squished a kicking corn bunting." Hear it here.

7. Dothraki includes interesting cultural metaphors in its idioms.

Athastokhdevishizar: Nonsense (lit. "fog talking")

Hash yer dothrae chek?: How are you? ("Do you ride well?")

Shierak qiya: Comet ("bleeding star")

Ki fin yeni!: WTF! ("By what failure!")

Thirat atthiraride: To dream ("to live a wooden/fake life")

Fonas chek!: Goodbye! ("Hunt well!")