The word **莫非** is formed through the grammaticalization of two classical Chinese components: **莫**, an archaic negative adverb meaning "do not" or "there is none," and **非**, a negative copula meaning "is not." Originally used in classical texts as a literal double-negative construction (e.g., "none is not," implying "all are"), it evolved into a fixed rhetorical pattern used to form conjectural or surprised questions in modern Chinese, equivalent to "could it be that...?" or "is it possible that...?" This transformation from a literal negation to a modal adverb expressing doubt or astonishment is a classic example of lexicalization, where a phrase fuses into a single unit with a specialized, non-compositional meaning.