After answering a question on GMAT Club, I realized that one type of error is not on every student’s radar. Many students are attuned to parallelism and are vigilant about eradicating modification errors. Same goes for the more typical grammar errors—students know about subject-verb agreement and pronoun-antecedent agreement.
But double negatives have floated below the radar for students, so I’d like to take this opportunity to talk about double negatives. I’ll start by talking generally about negative words, and then I will move into the particulars of double negatives.
https://magoosh.com/gmat/2014/double-neg ... t-correct/