When my wife graduated from college, my parents and I bought her a Kindle. Most of the items on it are hers, but I installed a copy of 'Every Word' on it because I love word games. The game is similar to Scrabble: you're given a group of letters and you form words from them to earn points. Unlike Scrabble, there is at least one word that will use all the letters you've been given, and that word is necessary to advance to the next level.
At lunch today, I discovered that the most obvious word I could form wasn't one approved by the system.
Me: This thing won't take "whipass".
Wife: That's because it should be "whoopass".
Me: I thought maybe they were looking for a Northern spelling.
Wife: "Whoopass" is the only form of the verb. There is no 'whip'.
Me: That's not a verb form, that's a noun. The noun should derive from a present tense form of "whipass". The game won't take "asswhip" either, and it really should.
Wife: There's "asswhippin'".
Me: Exactly! That's the gerund form, which implies that the verb "asswhip" should exist.
Wife: Maybe someone should design a Southern version of the game. You'd have more luck with it.