What is the theme in Changes: A Love Story by Ama Ata Aidoo?

Another prevalent theme in "Changes: A Love Story" is the theme of marriage as the novel's plot is centered around the failure of Esi's marriage with Oko and her remarriage to Ali. Oko is angry that Esi puts her career above her duties as a wife, and as a result, he rapes her. When Esi realizes she has suffered marital rape though it is impossible in her society since sex from his wife is a man's right, she decides to divorce Oko. Opokuya and Kubi argue about the car's movements as they do every morning. He feels he should drive the car to work and leave it parked all day while she takes the hospital vans to work, but she wants him to take the car off government maintenance so she can take care of her family properly. The argument always ends with one of them giving in, and the winner drives the loser to work.