Explain why Calpurnia speaks differently when she is around other black people.
Scout notices that Calpurnia speaks differently when she is around other black people at First Purchase African M.E. Church. Around the Finch family, Calpurnia uses more formal language. Scout thinks that Calpurnia should always speak the way she does around her and her family. She tells Calpurnia that she knows better and should not speak differently at church.
Calpurnia notes that it is a difficult situation to be in. She tells Scout that if she spoke formally to her friends and family at church, it would seem out of place. To them, it would not seem like her talking. She is concerned that they would think she is "puttin' on airs to beat Moses" (To Kill a Mockingbird, Chapter 12).
Again, Scout reminds Calpurnia that she knows better than to talk the way she does at church. Calpurnia tells Scout that "it's not necessary to tell all you know. It's not ladylike—in the second place, folks don't like to have somebody around knowin' more than they do." Calpurnia does not want anyone at her church to feel left out because of her talking. She also does not want to draw attention to herself or put on airs.