Junior Dos Santos in the space of about 2 years went from speaking no English to speaking very good English without the need of an interpreter. Machida spoke no English when he became champ and it took him about 5 or 6 years after that with the help tutors to speak decent English. Cyborg has lived in America for over 10 years and still has an ultra think accent. It's just dependent on your desire to really learn, if you have tutors to help you get rid of the accent. If I lived in a different country for more than a year and it seemed like that was going to be my new home, I would get a tutor.