The first difference between Edgar Allan Poe's "The Raven" and the two Shakespearian sonnets is metrical form. Both sonnets are written in the form of English sonnets, comprised of fourteen lines of iambic pentameter, with a rhyme scheme composed of three open quatrains followed by a couplet. Poe's "The Raven" is written in trochaic octameter, organized in six-line stanzas using both end and internal rhyme.
Although all three poems deal with the theme of love, Shakespeare's sonnets are generally optimistic in tone and celebrate the role of the poet in immortalizing the beloved. Poe's poem is melancholic, and portrays the poet as mourning a lost love; rather than creating a memorial which celebrates love, poetry serves to reinforce the poet's misery.
Finally, both Shakespearean poems are centered in a realistic world, in which the poet speaks with confidence and authority. Poe's world has a vaguely supernatural atmosphere, with the poet being an outsider, isolated from society.