Quote 1
It is impossible to say how first the idea entered my brain; but once conceived, it haunted me day and night. (2)
Obsession forces the narrator's version of reality into a narrow tube. If the narrator was thinking about inventing a cure for cancer or something, this tunnel vision might be a good thing. Here, his version of reality is dangerous to himself and others.
Quote 2
[F]or it was not the old man who vexed me, but his Evil Eye. (3)
The narrator attributes almost godlike power to the eye, as indicated by the capital letters. Perhaps he thinks the old man is inhabited by a horrible spirit.
Quote 3
And it was the mournful influence of the unperceived shadow that caused him to feel – although he neither saw nor heard – to feel the presence of my head within the room. (5)
This is an interesting passage because the narrator speaks for the old man. Throughout the eighth night the narrator imagines the old man's feelings, using his own experience as kind of a template, in a fit of pre-murder empathy.
Quote 4
And have I not told you that what you mistake for madness is but over-acuteness of the sense? (6)
Earlier, he refers to this condition as a "disease" – the implication being that it stems from his body rather than from his mind. Comments like these provoke questions about how the body and mind influence each other, and about the versions of reality of the people they belong to.
Quote 5
[D]o you mark me well I have told you that I am nervous: so I am. (7)
We know that feeling, like the way the old nerves clang after that seventh cup of coffee. The narrator obviously doesn't think nervousness is a component of madness. It also seems separate from his "disease."
Quote 6
They heard! – they suspected! – they knew! – they were making a mockery of my horror! (9)
It's quite possible he was right, though probably not for the reasons he gives. His creepiness probably shows through more than he knows. The fact that there are three of them suggests they were already really suspicious before they got there.
Quote 7
Hearken! and observe how healthily – how calmly I can tell you the whole story. (1)
In some ways, the story is told rather calmly, though "healthily" is a bit of a stretch. There is control in the narrative. This control is maintained in part because the narrator doesn't tell "the whole story," but select bits and pieces of it.
Quote 8
And then I thrust in my head. Oh, you would have laughed to see how cunningly I thrust it in! (3)
Go ahead. Snicker. Get it out of your system. We had to put these here because it has the word "cunningly" in it. This line is so silly it borders on hilarious. Good old comic relief. Clever Poe.
Quote 9
To think that there I was, opening the door, little by little, and he not even to dream of my secret deeds or thoughts. (4)
Such sad lines. His idea of being cunning seems so pathetic, and so creepy and destructive. We also wonder why the narrator is so sure the man doesn't suspect him. Is it because of the narrator's cunning, or the old man's lack of it?
Quote 10
There was nothing to wash out – no stain of any kind – no blood-spot whatever. I had been too wary for that. A tub had caught all – ha! ha! (8)
What exactly does the narrator use to do the dismembering? He makes no mention of disposing of the cutting implement. Is he being cunning, or did he just forget to mention it?
Quote 11
The officers were satisfied. My manner had convinced them. (9)
Has the narrator outsmarted the police officers, or are they hanging out with the narrator because they suspect him?
Quote 12
And every night, about midnight, I turned the latch of his door and opened it – oh so gently! (3)
If the old man leaves his door unlocked, it means he trusts the narrator, or (if he's bedridden) he might not have a choice. Either way, this is why we don't go to sleep until well after midnight.
Quote 13
And every morning, when the day broke, I went boldly into the chamber. (3)
We wonder if he stays up all night waiting by the door, or if he takes a break. It's not really clear. What a wretched, isolated picture of home.
Quote 14
And now a new anxiety seized me – the sound would be heard by a neighbour! (7)
Home can be an uncomfortable place when we fear our neighbors, or when we have suspicious characters like the narrator living near by. This common anxiety is brought to extremes in this story, echoing what we sometimes see if real life.
Quote 15
A shriek had been heard by a neighbour during the night; suspicion of foul play had been aroused. (8)
Would you call the police over one shriek? Would it alone be enough to get the police thinking foul play? We wonder what the neighbors and the police know that the narrator doesn't tell us.
Quote 16
I made up my mind to take the life of the old man, and thus rid myself of the eye forever. (2)
The fact that the man is old, and probably near death anyway, makes this bitterly ironic. To die is one thing, but to grow old, to spend the final years hated and despised is another.
Quote 17
All in vain; because Death, in approaching him had stalked with his black shadow before him, and enveloped the victim. (5)
This is a curiously structured sentence. At first it seems the narrator is simply personifying death. He's also referring to himself as Death, with a capital D – the nemesis of the "Evil Eye." The narrator is the stalker, and his shadow is black (because there is no light; this is before the opening of the lamp).
Quote 18
Yes, he was stone, stone dead. (7)
The word "stone" is repeated a third time, a few sentences later, which suggests that the word is important. This makes us think of the Medusa myth. When a person looks at Medusa and she looks back, or vice versa, the person turns to stone. This is just the kind of thing that would appeal to our narrator.
Quote 19
First of all I dismembered the corpse. I cut off the head and the arms and the legs. (8)
We don't bring this up to be gross, but to point out that this violent image is perhaps more disturbing than the image of the man smashed by the bed. For one thing, it's much more concrete and easy to visualize. It's also more invasively violent, even though the man is (we hope) already dead for this process.
Quote 20
It took me an hour to place my whole head within the opening so far that I could see him as he lay upon his bed. (3)
This strange time management technique suggests extreme loneliness. We learn later that the narrator has problems sleeping at night (and probably during the day). This moment is when we first begin to notice there's something funny going on with time.