It may come with being a native, but I can name -- right off the top of my head -- several Russian verbs that mean "to eat" (and nothing else): есть, кушать, жрать, лопать, трескать. I know only one English verb for it: "to eat". In Japanese, I know two: 食う (kuu) and 食べる (taberu). Foreign students usually are taught the latter first, while the former is postponed until advanced classes. I never heard "kuu" in 5 years of classes and know about its existence from anime. Such treatment is typically associated with vernacular. And I heard kuu in casual speech exclusively, until now.
However, Nozaki's new editor, Ken, employs the following construct in Nozaki-kun 11: "Yumeno-san, nanka kuimasu?". He is trying to be extra casual, yet... in keigo. Caught me by surprise completely. Nozaki-kun is the most rewatched show around here nowadays, to the point that it plays in the background, like a CD drama.