This is one of my favorite poems of all time, and part of that is because of the literary techniques Poe weaves into each line, focusing the reader's attention on both the depth of his love for Annabel Lee and on the tone of despair he generates.
Look at the repetition within this line:
But we loved with a love that was more than love—
(Bold added for emphasis.)
The depth of the speaker's feelings are made clear with this quick, repetitive use of the word "love." It was more than love, deeper than any emotion he has ever experienced.
I also love the alliteration in this poem, particularly lines like this one:
To shut her up in a sepulchre
Poe intentionally crafts this line to repeat this hissing s sound, effectively silencing the reader's mind. It's easy to feel that the speaker is shushing the world, demanding silence for the memory of Annabel Lee.
The alliteration is also well-crafted in this line:
The angels, not half so happy in Heaven,
The alliteration in this line brings attention to the fact that Heaven...
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