Christine, Mark Twain had the same problem with black dialect and he chose to phoneticize their speech. We don’t do that any longer. Today, just sprinkle in an occasional word or occasional speech pattern and the reader will “fill in” the rest in their minds. Hope that helps! Plus–think about this. To say that black and white speech are different is somewhat stereotypical thinking perhaps. I know many black people who speak better than Yale profs and many white people who speak worse than anyone else. It’s more of a culture thing, I think. If the character’s culture requires a different than “standard” speech, regardless of the race, then again, simply sprinkle in an occasional word or speech pattern and you’ll be fine. Trust the reader’s intelligence to get it–they will.

Just these three things help me avoid from getting caught