K.'s Arrest Shouldn't Stop Him from Living His Life Normally (Situational Irony)
In the novel's first chapter, Willem and Franz invade K.'s home to inform him that he is being arrested. After the guards make him wait in his room, K. meets with their superior, who informs K. that his arrest does not mean he will be imprisoned. On the contrary, the superior sees no reason why the arrest should prevent K. from going about his life and his work as usual. In this example of situational irony, K.'s expectation that he will be confined to prison is undermined by the revelation that his arrest involves no physical incarceration, despite what the term "arrest" usually denotes.
Before the Law (Situational Irony)
During their conversation in the cathedral, the priest and K. discuss a parable (published elsewhere as "Before the Law") in which a man spends his entire life waiting to enter a gate that gives him entrance "into the Law." Before he dies, the man asks the guard who will not admit him why no one else has tried to enter. The guard says no one else has tried because the gate was made specifically for the man; the guard then shuts the gate. Kafka concludes the parable with an instance of situational irony: despite the man's belief that eventually he could enter the Law, he learns that he has been waiting in vain. Moreover, his understanding that everyone wants to enter the Law is undermined by the revelation that the gate was made for him alone.
K. Never Learns What Crime He Supposedly Committed (Situational Irony)
In the novel's final chapter, the narrator comments that K. never came into contact with any of the higher court officials and also never learned what he is accused of. By this point in the story, however, K. is so broken and demoralized by the futility of resisting his trial that it no longer matters what his actual crime was. In this instance of situational irony, Kafka emphasizes how the reason for K.'s arrest is irrelevant to his trial. What matters most is that he is accused and presumed guilty, and it is futile for him to question the court's inscrutable authority.
Block's Trial Hasn't Begun (Situational Irony)
Even though Block has spent five years and lost his livelihood defending his case, Huld reveals to K. that Block's trial hasn't even begun yet. Despite his efforts, Block, unlike K., is never given a first hearing; instead, he is kept in a state of servility to the court and to Huld. In this example of situational irony, Kafka illustrates the illogical and capricious nature of the court: rather than treating defendants equally and delivering justice, the court behaves inconsistently, ensuring its inscrutable power over the accused.
