This is a magnificent piece of poetry. The hypnotic monotony of rhythm reflected the speaker's frame of mind. The poem is clearly about the sorrow he experienced over the death of his wife and her ideal, spiritual love. The raven, being a symbol of death, and the lines, "Other friends have flown before-On the morrow he will leave me as my hopes have flown before," meant that he was afraid death might abandon him, leaving him comfortless. Then he sits in front of the bird wondering why the raven croaked "Nevermore". The raven is trying to tell him "she shall press, ah, nevermore", but he thinks the bird is lying because his grief is so great, and he doesn't believe that Lenore's death is final. When he realized that the raven is trying to tell him that her death is final, he becomes angry and upset. He begs the raven to tell him if she is in heaven, whill the angels love her and take care of her the way she should be.
In the last four lines of the poemwhere "the raven, never flitting, still is sitting, still is sitting," and the shadows that "shall be lifted-nevermore," mean that the raven is a symbol of the wisdom and knowledge that he will always have memories of Lenore, but that her death is final. He will always mourn her.