Mama and Walter have different views on the world and money. Walter sees life as money and Mama sees life as having a family and having something to be proud of. Walter does not see his job as a job that will get him a future and wants more in life, which Mama does not understand. She begins to think Walter has changed and does not appreciate his life enough.
Mama VS. Walter
Beneatha is conflicted with her true self and men in her life form these questions like George and Asagai, who pull at both ends of this issue. George wants her to look and act like an average American and be "presentable", while Asagai wants her to tap into her culture and present as the Nigerian woman she is.
Beneatha VS. Self
Walter VS. Society
Walter struggles in society due to his job. He feels he is just serving men by driving them with set commands, which creates the sense of him having no future and his life will forever be the nothingness of serving people and not having money to support his family on its own.