應

1. Response and Fulfillment: Answering a summons or reply to a question; fulfilling a promise; bringing an internal state into correspondence with an external demand.

2. Correspondence and Fitting: A physical or conceptual match between two things in scale, nature, or function.

3. Modal Necessity: Logical necessity derived from circumstances ("Given X, Y is the fitting response").

• Modal Auxiliary: When preceding another verb (應 + Verb), it functions as "should," "must," or "is expected to," establishing a logical consequence or expectation of a future state.
• Main Verb: When taking a direct object, it denotes the act of answering, responding to, or matching.
• Parallelism: In philosophical or poetic contexts, often marks the second half of a cause-and-effect pair, signaling that the line is the complementary response to the stimulus described in the first.

Contrast with 當 (dāng): While both can be translated as "should," 當 typically refers to status, duty, or the appropriateness of a specific time or role. 應 focuses on the internal logic of a situation or a natural reaction.

• Variants: Simplified variant 应 (U+5E94); specialized semantic variant U+786C.

// Tang-period readings: //qiəng, *qiə̀ng.

Be cautious when distinguishing between requirement (command) and expectation (prediction). Depending on context, the glyph may imply either "I demand it be" or "I suspect it will be."