In "The Raven," by Edgar Allan Poe, is the raven really talking to the narrator or is the narrator just imagining the raven talking to him?

Like any bird that "talks" or "speaks," the raven is merely mimicking a word or sound that it has heard before. It does not carry on a conversation--"nevermore" is the only word it ever utters (at least that is what the narrator thinks he hears)--and it doesn't really seem to pay much attention to the narrator as it perches at a safe distance on the head of a bust. When the narrator discovers that the bird can only speak one word, he nonetheless continues to ask questions that can still be answered sensibly with the answer "nevermore." The narrator, who at the beginning of the poem is already devastated by the "loss of Lenore," is on the verge of losing his sanity at the end as he asks the bird to predict his future with the "lost Lenore."