I am guilty of changing my speech pattern, but not only at work I change mine with every different environment. I always have I think its a self-defense mechanism that I developed when i was a child. From different people saying stuff like, "Uhhh she think she a white girl! or Ugh she talk like she's to much!" So I now talk like whomever I'm around. If I'm with my dads side of the family, they are all country folk and talk with a slow drawl, so that's how I talk when I'm with them. When I'm with my mom's side it's more of a proper talk with some slang, like ya'll and gonna etc. When I'm at work it's more of the "white girl talk" But unfortunately that is my actual speech pattern, I never thinking about how I'm speaking at work, but I am very concious anywhere else, until I get into my groove. I find it funny sometimes, like the closer I get to East Texas (where my dads family is from) the countrier I start talking. I just subconsiously work myself into my new speech pattern.