Teaching native languages
The students are painfully aware of this irony, and they chide Marin the whole novel about it. They want to know why they should have to learn a language they already know. When he defends the meaningful nature of written language, they respond with a technically-valid opinion that language is utilitarian in nature. In other words, the situational irony of their already knowing French shows a dramatic irony that they don't perceive. They don't understand the value of art because they are still innocent.
The relevance of Nazi Germany
The ironic ennui of the classroom reaches its peak when Marin introduces The Diary of Anne Frank. Perhaps no book could be as inherently meaningful and important to French teenagers, seeing as the history of Paris is famously darkened by the invasion of Germany, and seeing as Anne Frank's Diary shows that moment in history from their own adolescent point of view. Yet, they don't see why they should care at all. Their ironic detachment from the book's relevance is a kind of personal torture to Marin.
Souleymane's language difficulties
Souleymane is a deeply ironic character. He often receives the worst treatment because he isn't a native French speaker, and therefore, his essays and reports are often subpar, but not because he is stupid. Rather, he is deeply insightful and intelligent. When he turns in a photography album instead of an essay, he proves his intellect. His language difficulties are ironic because they conceal his true intellect. They are also ironic in their shape—he has no problem insulting Marin in French.
The expulsion of the foreigner
Although Marin understands the meaningful, valid emotional experience of Souleymane, he is unable to convey that properly because in truth, Souleymane's behavior is worthy of discipline. When his mother tries to defend him, the differences between the French culture and Souleymane's family culture lead to a rift that makes his treatment even worse. Although no one would claim xenophobia, the question is on the table—would another more "French" student have received the same punishment?
Esmeralda and the unseen
Esmeralda is clever in the worst ways for Marin. He needs to hold the attention of a class that struggles to respect him, and Esmeralda is perfectly suited to undermine his authority. Her wiles are rooted in her skills in the linguistic domain of "plausible deniability." Although she does consistently expose Marin's weaknesses and insecurities, she does it in a way that she can always come out with her hands clean. In other words, there is a situational irony because the student is masterful at playing dumb. Her cleverness in negative spaces leads her to admit a deep attraction to Platonic philosophy. She honors Socrates in theory while disrespecting Marin in practice.
