User blog comment:Mrgod11234/Can Zoro use haki,And big mam and kadio strength/@comment-1595565-20110725051511

No, he can't and he won't. Not everyone needs to learn to use haki. One person learning all three on one crew is enough. Haki makes a character's abilities less impressive. Zoro doesn't need it, and it would only diminish his overall raw abilities as a fighter if he did learn it.