The story has a repeated metaphor. A metaphor is comparing two things without using "like" or "as". The Narrator compares his eye to a vulture.
The Story has a lot of dramatic irony. Dramatic irony is when the reader ore audience doesn't know when something is going to happen. The story shows dramatic irony by having the narrator stalk the old man for eight nights and the reader doesn't know when he is going to strike.
The story has a big character contradiction in it. Character contradiction is where a character does something that they wouldn't usually do. The character contradiction shown in the story is when the narrator says that the old man didn't do anything to him and that he loved him, but the narrator ends up killing the old man