pero
ES [ˈpeɾo] · Spanish for “but” · same spelling as Czech pero (a pen, a feather)
Spanish songs are full of pero and for my first few months every one of them handed me a pen. In Czech a pero is the thing you sign with, or the feather it used to be, so any chorus turning on pero kept dropping stationery into perfectly good heartbreak.
It means but. Once your ear takes that in you cannot get the other reading back, which is a small shame. The wrong one was more interesting.
Nothing joins these two. Spanish pero was squeezed out of Late Latin per hoc, by this, which wore down over centuries into a plain contradiction and ended up as the everyday but. Czech pero is inherited straight from Proto-Slavic and goes back to a very old word for a feather or a wing. The good part is where that Czech word keeps its relatives. The same ancient feather turned into Latin penna, and penna is where English got pen. So Czech pero and English pen are distant cousins across two language families, while the Spanish word sitting between them is a worn-out Latin phrase meaning by this.