Concept #69 question#

If I was writing a film in say, South Africa I would have my actors watch some films that showed the people from South Africa speaking .  I would then give them a substantial amount of time to practice their wording. By the time that I call them to begin the movie I will test them to ensure that they have indeed practiced and deserve to be in the movie.  If one of my actors did not, then his/her replacement will immediately take over because I can't have people who are slackers make my movie look bad.