Double Negatives
Incorrect : He is not afraid of nobody.
Correct: He is not afraid of anybody. Or He is afraid of nobody.
Note: Two negatives in the same clause produce a positive meaning. Therefore, two negatives in the same clause should be avoided. When, “not” is used, “nothing" changes to “anything”, “nobody” to "anybody', 'no one' to "anyone' and "nowhere' to “anywhere'.
For example:
I know nothing.
I do not know anything.
They have nothing to say.
They do not have anything to say.
He was found nowhere.
He was not found anywhere.