Leif isn’t thinking the Sønska word for “thorn”; he’s thinking a phonetic version of the Ceannic one. It sounds something like “Thawn” or “Thoan”. Listen to this video on Norwegian vowels (starting around 1:07) to hear a long “å” out loud.
(In Ceannic, the languages are called “Ceannic” and “Sonheic”. In Sønska, they’re “Sønska” and “Ceanska”.)
Thorn (thinking): So that’s the gardener, hm? Leif . . . he seemed nice. Hope he didn’t take off so fast because I said the wrong thing. I really need to brush up on my Sønska.
Thorn: Network? Connect me to a translation crystal, Northern Ceannic to Sønska.
Thorn (thinking): First I’ll look up the conjugation of “to keep” . . .
Leif (thinking): So that’s one of our new foreign guards. “Thån.” He’s even pretty good with the language.
Question is . . . was he good enough to be flirting with me on purpose?
No, Leif, he isn’t that good…Go with it any ways!