Answer:
In "The Cask of Amontillado" following sentence is used by the author as irony to show that Fortunato is unaware of the danger ahead:
"Fortunato possessed himself of my arm; and putting on a mask of black silk and drawing a roquelaire closely about my person, I suffered him to hurry me to my palazzo."
Also, another irony is:
"Enough," he [Fortunato] said; "the cough's a mere nothing; it will not kill me. I shall not die of a cough."
Explanation:
In "The Cask Of Amontillado", we see that Fortunato is not aware of the danger ahead of him. He is the one that hurries Montresor towards the catacombs because he has no idea that he was hastening himself to his own death.
The story itself is filled with situational irony. Situational irony simply refers to situations which took place and are the opposite of what really happened.
In the story, when Montresor decided to take Fortunato back because of his cough, it was Fortunato who still insisted to go. The excerpt that explains that is above.
