Ofcourse Margo knows how to speak english. He's got thick accent and just didn't wanna sound funny in the eyes of many viewers.

JMM and MAB spoke broken english when Larry Merchant interviewed them after their bout...

Heck, even Pac doesn't speak english that well but he's trying his best and not ashame of it. Margo should do the same thing too especially knowing that he's an american born citizen.