I understand bene to roughly mean well, good, or rightly so from Latin, while neg- coming from Latin negare to roughly mean deny, negate, or against.
The words benefit, beneficial, and benefactor all represent a person or characteristic that yields a positive result or influence. Do any of these words have an antonym that includes the neg- affix? Are there any positive bene-based words that have a neg-based word as its antonym?
Mono- and poly- seem to be frequently paired in an antonymic relationship — does this occur with bene- and neg-?
*Background: I started titling a pro and con list with benefit, and found myself searching for negefit.
Best Answer
No, bene- and neg- are not used to form antonyms in either English or Latin. Their root meanings of "good" and "deny" are roughly opposed, but not antonyms in English either.
As others have mentioned, mal-, meaning "bad" is the typical antonym to bene-, as in benediction/malediction (literally "good speech", "bad speech").
Posi- may seem like it should oppose negi- because of the positive/negative pairing, but it actually comes from a root word meaning "put" or "place." Affirm- is probably a better opposite to neg- as in affirmative/negative and affirmation/negation.