Dramatic irony occurs when the audience knows more about the situation in a literary work than the characters do. Indeed, dramatic irony is built right into the title of Buchi Emecheta's novel Second-Class Citizen, and it is also woven directly into the plot.
The story's protagonist, Adah, has major dreams. She wants to go to college and live in England and become a writer. Her high social status in Nigeria allows her the opportunity for at least some education, though she has to fight her family to go to school and her school days are limited by her parents' deaths. Even with her unfinished education, Adah is considered a first-class citizen in Nigeria, and she has a job that pays well even after she marries Francis and must leave school.
Yet the story's title is Second-Class Citizen. Readers, therefore, know that Adah's status will not last, particularly after she and Francis move to England. We readers know that the situation Adah will face in Britain is far different from what she imagines.
Adah believes that life in England will be wonderful. She dreams of furthering her education, getting a good job, and finding more opportunities for her children. Yet we readers are forced to smile sadly at Adah's hopes because we know that in England, she will encounter prejudice like she has never known before. We know that because she is Nigerian, she will be considered a second-class citizen and that life will be very different from the privileged position she held in Nigeria. Herein lies the dramatic irony, at least for a while—readers know what Adah does not.