Calpurnia speaks really fast and her vocabulary is phenominal. Why does she speak really so fast?

Calpurnia changes the way she speaks according to where she is and who she is with. Instead of using proper English, she reverts to "colored talk" when she's at church so she won't offend the blacks. She says that she doesn't want to seem uppity to the other blacks by talking better than they do.

that's interesting.