Boom! Nobody knows! This is what looks like a negative, kind of is negative but has no positive. Not in linguistic manner. "Návidím ho" does not exist. The opposite of nenávidím would be "miluju ho" (I love him) though that expression has its own opposite "nemiluju ho". At the same time "nemiluju ho" is not the same as "nenavidim ho". I do not love him vs. I hate him is obviously different.