The word "唠叨" is formed through a process of reduplication, where the single-character morpheme "唠" (meaning to chatter or gab) is doubled to create a new, expressive word. This repetition mimics the very action it describes, visually and aurally evoking the sense of continuous, repetitive, and somewhat wearisome talk, like a nagging or going on and on, thereby intensifying the core meaning into a state of persistent verbal fussing.