The word "闻到" is formed by combining the character "闻", which denotes the act of perceiving through the sense of smell, with the character "到", which conveys the idea of reaching or attaining a result. In this compound, "到" functions as a resultative element attached to the verb "闻", effectively creating a single lexical unit that implies the successful completion of the smelling action, specifically, having detected or become aware of a scent. This formation highlights a cause-and-effect relationship within the word itself, where the action leads to a tangible perceptual outcome.