Precise Word Choice
Diction is choosing the word whose exact meaning, connotation, and register fit the sentence — 'said' vs 'demanded,' 'thin' vs 'scrawny' — the difference between adequate and precise writing.
Connotation does the heavy lifting: ‘assertive’ praises while ‘pushy’ criticizes the same behavior. Strong diction also prefers concrete words over abstractions — ‘limped’ shows what ‘walked badly’ only tells.