In Chapter 10, as Jake and Bill prepare to travel from Bayonne to Pamplona, they head to their hotel to pay the bill. Jake notices an unwelcome visitor skittering across the floor:
While we were waiting I saw a cockroach on the parquet floor that must have been at least three inches long. I pointed him out to Bill and then put my shoe on him. We agreed he must have come in from the garden. It was really an awfully clean hotel.
This passage is a prime example of the way Hemingway imbues his prose with irony to give Jake’s narration its sarcastic tone. Jake does not earnestly remark that it is a clean hotel, but instead wields verbal irony to mean the opposite: the presence of the cockroach is proof enough of its uncleanliness. This gives the narrative a somewhat biting, sardonic tone in this moment, thus underscoring the sense of cynicism and discontent lurking in Jake's temperament. And yet, the ironic remark also hints at Jake's relative passivity—he's not happy that there's a cockroach in the hotel, but all he does is make a snarky aside about the matter, thus illustrating not just his cynicism, but also his jaded, somewhat acquiescent nature.
Although Jake and his fellow aficionados go to great lengths to romanticize bullfighting and its sacred significance in The Sun Also Rises, theirs is not a universally shared opinion. In an exchange between Jake and a waiter in Chapter 17, Hemingway uses irony to demonstrate the waiter’s distaste for the sport:
“Badly cogido through the back,” he said. He put the pots down on the table and sat down in the chair at the table. “A big horn wound. All for fun. Just for fun. What do you think of that?”
“I don’t know.”
“That’s it. All for fun. Fun, you understand.”
“You’re not an aficionado?”
"Me? What are bulls? Animals. Brute animals." He stood up and put his hand on the small of his back. "Right through the back. A cornada right through the back. For fun—you understand."
This exchange occurs in the aftermath of a particularly bloody day of the fiesta in Pamplona, in which a man is killed during the running of the bulls. The waiter uses verbal irony to talk about the "fun" of bullfighting, juxtaposing his repeated insistence of the entertainment of the sport with comments about its brutality and violence. The irony of his comments calls attention to the uncomfortable reality of the violence of bullfighting, despite it also being a theoretical source of entertainment for Jake and his compatriots. This exchange also highlights the gulf between the view of aficionados and the opinions of laypeople who may not have such a reverent view of the activity: Jake's passion for the sport is, in some ways, a passion for bloodshed. This is an especially complicated truth to face in light of his experience and trauma during the Great War. In The Sun Also Rises, it takes an outsider—in this case the non-aficionado waiter—to offer this alternate perspective.
In Chapter 19, Brett sends Jake a telegram to come find her in Madrid, where she has been staying with Romero. He instantly agrees. Sending a telegram back to her, he ends his message: “Love Jake.” Tortured by his unconscious urge to be with Brett despite her continual pursuit of other lovers, he wryly reflects on his situation:
That was it. Send a girl off with one man. Introduce her to another to go off with him. Now go and bring her back. And sign the wire with love. That was it all right. I went in to lunch.
At face value, nothing here conveys Jake’s dismay. But Hemingway often caches Jake’s full emotion in a layer of bitter irony, and this verbal irony is on full display here. The phrases "that was it” and “that was it alright” are not genuine expressions of satisfaction but the exact opposite. Jake is anguished by his love for Brett despite his consistent willingness to act as matchmaker, and Hemingway succinctly sums up the pain and discomfort of this predicament in this instance of verbal irony, which ultimately conveys Jake's frustration at his own inability to get what he really wants.