‘反之’ is a conjunction meaning ‘on the contrary’, ‘conversely’, or ‘in contrast’. It literally combines 反 (fǎn), meaning ‘to reverse’ or ‘opposite’, and 之 (zhī), a classical pronoun meaning ‘it’ or ‘this’, together forming an elegant, concise way to introduce a contrasting idea—especially one that reverses the logic or direction of the preceding statement. It’s common in formal writing, academic texts, and logical reasoning, but also appears in spoken Chinese when speakers want to express a sharp contrast with rhetorical clarity.

This term often follows a cause-effect, conditional, or comparative clause and signals that the opposite situation holds true under reversed conditions. It does not stand alone; it always connects two related ideas, with the second being the logical inverse of the first. Because of its classical roots, 反之 carries a slightly formal or literary tone—not used in casual chit-chat, but perfectly natural in reasoned discussion, advice, or explanation.