是非
shìfēi · HSK 7
right and wrong
⚖️ 是 (right/correct) + 非 (wrong/not) = right-and-wrong; squabble over who's right
是 means yes/correct, 非 means not/wrong, so 是非 literally pairs right with wrong. It covers both the abstract right-and-wrong of a matter and the petty quarrel that erupts when people argue over it.
是 — sun 日 + 正 (correct/upright)
Originally a compound suggesting 'the sun 日 directly overhead'—straight, correct, true. From this concrete sense of 'right' or 'this very thing,' 是 came to mean 'this' as a demonstrative, and later the modern copula 'to be / is.' The 'correct' meaning survives in words like 是非 (right and wrong).
非 — two opposing wings 羽-like form
Originally a pictograph showing two wings spread in opposite directions, symbolizing things facing away from each other. From this 'opposition' image came the meaning 'not' or 'wrong.' It is also used as a phonetic component in many characters like 排, 悲, and 罪.