I’m on Level 26 and just came across 訴える (うったえる). As far as I can remember, this is the first time on WK I’ve seen a っ appear in a reading where it’s not taking the place of つ when making a compound, like 出発 (しゅっぱつ) or 必死 (ひっし). I know it’s very common for in mainly hiragana words like びっくり or ぴったり, or when in the て or た form, but it’s rare-ish to find a っ in a root, no? Anyone got any fun etymology?
Dictionary just says that it’s a sound change from the verb form うるたう, and so it seems like it just is easier to say.
Another one with the small つ in the root off the top of my head is 則る (のっとる). Similarly that is a sound change from のりとる.