In "The Cask of Amontillado" do the choice of words, concrete images, and figures of speech aid in creating the atmosphere of the story?
The simple answer is of course! Those techniques are what writers use to creat not only atmosphere, but suspense, plot, character, and conflict. If you look at specific examples from the story, you can see how Poe used those techniques.
At the beginning, Montresor states of his revenge, "I must not only punish but punish with impunity." The use of "impunity" indicates that he will be thorough and merciless; he emphasizes it. This takes the suspense and horror up a notch. Then, the story begins "during the supreme madness of the carnival season." Supreme madness, huh? Ultimate insanity? Can this be tied to the narrator himself? Yes, I think so. Once in the tombs, the concrete image of "long walls of piled skeletons" definitely enhances the mood of horror. Then, once Fortunado is entombed, there is "a succession of loud and shrill screams, bursting suddenly from the throat of the chained form, seemed to thrust me violently back." The word choices here are intense; "loud and shrill screams bursting", and Montresor was "thrust violently". That is pretty horrifying, and takes the suspense up a notch. And then, after the deed is done, Montresor states, "My heart grew sick," figurative language (personification) that symbolizes the tiny second of remorse that he has, which adds depth and reality to the story itself. All of these are examples of Poe's abilities to use words to create a great story.