Bad news, Game of Thrones fans: You are mispronouncing Daenerys’s honorific, Khaleesi. But don’t feel bad. On the HBO show, her smitten man-servant Jorah has been saying it incorrectly as well; the more accurate pronunciation should be “KHAH-lay-see,” not “ka-LEE-see.” That’s according to David J. Peterson, the language creator responsible for all of the Dothraki and Valyrian dialogue spoken on the show, and he’s driven mad every time he hears it. “Ugh. God. That’s not how it’s supposed to sound,” said Peterson. “The vowel change bugs me.” As the architect of the language’s grammar and pronunciation rules, he’s the only one who can correct it with authority, but he lost the battle to correct the pronunciation on the show early on. “The producers decided they liked the other way better. They probably thought most people were pronouncing it that way anyway, which is true.”

Of course, Peterson did not coin the word Khaleesi. It existed in George R. R. Martin’s A Song of Ice and Fire series, along with a couple dozen others dreamed up by the author. But Thrones producers decided we needed to hear Drogo and his people speaking more extensively in their native language and searched for someone to flesh out a whole language, just as Marc Okrand did with Klingon and Paul Frommer did with Avatar’s Na’vi. Peterson, who has a masters in linguistics from the University of California–San Diego and founded the Language Creation Society, spent twelve to fourteen hours a day, every day, for two months working on the proposal that landed him the Thrones job. When he was finished, he had more than 300 pages of vocabulary and notes detailing how the Dothraki language would sound and function. “The application process favored those of us who were unemployed at the time, which I was,” Peterson laughed. (He also generated some White Walker lingo that ultimately went unused in the pilot.)

Studious fans of the series already know it was Peterson who decided that the Dothraki people would have no word for thank you. And before the producers even asked him to, he even got a jump on High Valyrian, which we first heard dramatically spoken at length by Daenerys in Sunday’s episode. “I needed to translate something into Dothraki that required a word for a specific type of bread that I didn’t think would be native to the Dothraki but which I thought a stable civilization, one that wasn’t nomadic, would have come up with. So I created the word in High Valyrian — havon, meaning bread — and borrowed it into Dothraki.” He’s coined nearly 4,000 words in Dothraki.

Danaerys unleashed High Valyrian in spectacular fashion, liberating the Unsullied, ordering up dragon fire, and explaining to the cruel slave trader Kraznys that he was toast. To help actress Emilia Clarke deliver this monologue as Daenerys, Peterson did what he does for all of the actors who must speak his tongues, translating the scripts and sending along audio files of himself reading the dialogue. After seeing the final product of Sunday’s episode, Peterson blogged that Emilia Clarke “really does speak High Valyrian like a natural. She missed a word or two here or there, but such will happen.” High Valyrian is the Latin of Martin’s world, the mother language, and to elevate and differentiate it from the harsh, guttural sounds of Dothraki, Peterson made Valyrian a far more mellifluous tongue; in fact, he thinks he made it almost too nice on the ears. “Seriously, it drives me nuts. It’s like the [Valyrian] language has a bow on it. These words are just so stupid pretty. Like the word for copper is ‘brāedion’ [pronounced: BRI-dee-on, where the first syllable sounds like the first syllable of “bridle”]. Bronze is ‘brāedāzma’ [pronounced: BRI-dah-zmah, again like “bridle”]. How do I get away with that? This one’s funny: The word for chain is belmon.” Peterson laughed. (Linguist humor!) “That’s clearly a shout-out to [the video game Castlevania II:] Simon’s Quest.” (Clearly!)

Thrones showrunners David Benioff and D.B. Weiss credit Peterson with having come up with a lot of “really, really vile things to say in Dothraki” that they didn’t write themselves, and he has tried to top himself with the more common, bastardized version of Valyrian spoken by Kraznys. “Part of the fun doing the Low Valyrian is that I could really take a bat to pretty, proper High Valyrian. Sometimes I imagine High Valyrian being a piñata of a princess castle,” Peterson said. So far this season, Kraznys’s colorful line from episode three — “And this because I like the curve of her ass” (translated: “Si kizy vasko v’uvar ez zya gundja yn hilas”) — has gotten a big reaction online.

Peterson said Dan Hildebrand, who plays Kraznys, did an admirable job with massive amounts of Valyrian dialogue. “He tends to devoice a lot of the fricatives, but I take that purely as an idiolectal variant. He’s very convincing.” (If you want to translate the translator, go here for a quick tutorial on fricatives.) Worse is when words or parts of phrases get cut off in editing. It’s the kind of thing only Peterson would notice, but as the guy who spends his days dutifully coining vocab, it stings. “It’s like, no, you can’t drop that! That word is kind of important.” But Peterson doesn’t dare take shortcuts, however undetectable they might be. Too many people are learning the language. Seriously. “I’m always thinking of them, like someday down the line, someone’s gonna spot this.” And how’s this for potential validation? Martin now periodically asks Peterson to translate passages for the forthcoming sixth book in the Ice and Fire series, The Winds of Winter. “He’ll e-mail me once in a blue moon, and then I’ll reply and I won’t hear back,” Peterson laughed. “He’s a busy dude. I’ll have to wait to see if he used anything when it’s published.”