And the only word there spoken was the whispered word, ‘Lenore?’
This I whispered, and an echo murmured back the word, ‘Lenore!’—

In this quote, which appears in Stanza 5, the speaker investigates the tapping on his door and, seeing no one, calls out Lenore’s name into the darkness. The eerie atmosphere of the night and the mysterious knock have prompted the speaker to hope his beloved Lenore, albeit dead, could somehow be his visitor. This moment shows the speaker’s suggestible state of mind and how Lenore is at the forefront of his thoughts.

Tell me what thy lordly name is on the Night’s Plutonian shore!
Quoth the Raven ‘Nevermore.’

These lines from Stanza 8 introduce the raven’s famous refrain. By suggesting that the raven has come from “Night’s Plutonian shore”—which refers to Pluto, the Roman god of the underworld—the speaker implies that the raven is a messenger from the dark underworld, associating it actively with death. The word “nevermore” highlights the hopelessness of the speaker’s situation and his unending grief.

‘Quaff, oh quaff this kind nepenthe and forget this lost Lenore!’

The speaker says this line, which appears in Stanza 14, quietly to himself after the raven’s refrain causes him to reflect on Lenore’s absence. He refers to “nepenthe,” which is a mystical drug, found in ancient Greek literature, that helps one forget. He admonishes himself to take advantage of the distraction and forget Lenore, but his mood starts to become more desperate as he struggles to find succor for his grief. He finds Lenore’s memory so painful that he believes only forgetting her can relieve him.

Get thee back into the tempest and the Night’s Plutonian shore!
Leave no black plume as a token of that lie thy soul hath spoken!
Leave my loneliness unbroken!—quit the bust above my door!’

These lines from Stanza 17 contain the speaker’s last words to the raven. The speaker’s mental state has completely deteriorated, leaving him to rage at the raven for answering his questions with the word “nevermore,” despite only ever hearing the bird say that one word. Because we can read the raven as representative of the speaker’s grief, when he asks it to leave without a trace, he is effectively ordering his sorrow over Lenore’s death to leave him.