Bigger’s name rhymes with the n-word, and that’s probably not a coincidence. It is also an ironic name: Bigger is unfortunately little, in terms of his place in the world and his relevance to people who do have wealth and power. He is small, powerless, battered around by larger (or bigger) social forces that shape him and then consume him.
Buddy’s name is also appropriate. Though we see little of him in the book, he is Bigger’s friend (or buddy). He looks up to his older brother and wants to be like him. When he sees Bigger in prison, he says he has a gun, then asks who framed him so he can go out and take care of those guys himself.
Jan Erlone’s name suggests "foreignness" and allows American citizens to see him as alien instead of one of their own, even though Jan was born and raised in the United States. This allows the anti-Communist forces in the book to continue to see communism as an alien ideology, as un-American.
Wright frequently explains precisely how Bigger is feeling and why he behaves the way he does. For example, after Bigger scares Gus by threatening to kill him because he was late to their rendezvous, Wright explains that Bigger can’t face his own fear of robbing white people or facing white society in general. So instead, he acts out at people like his friend Gus.
The characters that grow up or live on the South Side are invariably black and poor. They fill their hopeless lives with religion (e.g., Bigger’s mother) or alcohol (e.g., Bessie) to try to feel better about their lack of options. White people deliberately try to keep blacks in this particular area. Overcrowded and insufficient housing, along with poverty and segregation, create a mass of people who feel trapped, angry, and afraid. We see this in various characters in the book but it is exemplified in Bigger, who is held up in court as the symbol of what happens when a young man is prevented from fulfilling their full potential.
The black characters in the book speak differently from the white characters. Their speech could indicate their lack of education as well as their relative isolation from white society.
The Daltons sound genteel and educated, indicating their social position and education. This is part of why Bigger misunderstands Mary’s motives. When she speaks to him like he’s an equal, he thinks she’s making fun of him.
Mr. Buckley uses a pompous, self-important style of speech in order to emphasize his relative importance in the world and others’ lack of importance.