In "The Cask of Amontillado" is the narrator reliable or unreliable and why?
The narrator in this story is a bit of a crazed, jealous, spiteful man who ends up bricking his friend behind a wall in order to ensure his death, and, he does it all with panache and enjoyment. So, I wouldn't rely too heavily on him-he's not necessarily trustworthy. The story is told from his point of view, so it is first-person, and, because of the things I listed above, he isn't a reliable narrator. He might be relied on to have told the events of the actual story accurately as he can, but before the story occurs, we don't really get an objective picture. For example, why is he so angry with Fortunado, and did poor Fortunado really deserve such cruelty? The only clues that we get to these questions are Montresor's words himself. He states,
"THE THOUSAND INJURIES of Fortunato I had borne as I best could, but when he ventured upon insult I vowed revenge."
So, we can't say with any certainty that the narrator's reasons for revenge are justified. We don't know the details, and can't make a judgment call for ourselves. Hence, the narrator is a bit unreliable, since his entire mission is based around something that he deems worthy of revenge, without telling us what it is. I hope that those thoughts help; for your other questions, I suggest submitting them separately, since the format of the website allows one question a day. Good luck!
Montresor is an unreliable narrator. We can't trust what he tells us for several reasons.
To be persuasive, a writer or storyteller (this is apparently a deathbed confession) must meet two criteria. First, his reasons for what he is doing (or has done) must be sufficient. As mentioned in the answer above, Montresor doesn't give us any real reason for why he killed Fortunato. The few reasons he offers—that Fortunato has injured and insulted him—are not concrete or specific. They are not sufficient—not enough—to justify murder, to make us feel that, yes, Fortunato deserved this fate.
Second, to be persuasive, the storyteller must offer evidence that is relevant or relatable. Again, Montresor gives us no evidence that the punishment fits or is relevant to the crime, since we don't truly know what the crime is. Walling him up bears no relationship, as far as we can understand, to what Fortunato has done.
Because Montresor leaves out so much information that we need to evaluate his actions, we can't rely on him. We strongly suspect that were Fortunato or an omniscient narrator to tell the story, or were a reporter to investigate the events for an objective news report, a very different version of the story would emerge.