According to "The Philosophy of Composition, Poe choose the word 'Nevermore" as the refrain in "The Raven" Because of the sounds of the "o" and the "r"
Explanation:
In the Philosophy of composition he talks about the right elements that are necessary to create a good piece of literary work. In the specific case of The Raven and the use of the word Nevermore, it makes a contrast of sound between consonants and vowel and he plays with it to create a phonetic effect besides it has the same vowel sounds like the name Lenore.
In his essay, "The Philosophy of Composition," Poe explains that he wanted to have a strong word for the Raven to say. It had to be "sonorous and susceptible of protracted emphasis".
These considerations led him to the conclusion that the word should contain the vowel "o" connected with the consonant "r."
After deciding these characteristics, the first word that came to his mind was "Nevermore."
