The other day I came upon the phrase, "Is non modo hoc non perfecit." (It was followed by an 'ut' clause.) Try as I might, I simply couldn't get a meaning to fit.
That got me thinking about double negatives. I know in English double negatives are awkward and boorish and gramatically incorrect, but are they allowed in Latin? (Or maybe I'm just missing something completely....^_^;;)