The narrator is nameless, which suggests that his principal job is to narrate. We don’t know much about him, and our attention is drawn instead to the strangeness going down in the House of Usher; it’s the narrator’s place to take us on a tour of the Mansion de Fear.
One of the most interesting things this narrator does is insist, over and over again, that all attempts to accurately portray the weird happenings of the House of Usher are essentially futile. Observe:
…an influence whose supposititious force was conveyed in terms too shadowy here to be re-stated. (12)
I should fail in any attempt to convey an idea of the exact character of the studies, or of the occupations, in which he involved me. (16)
I would in vain endeavour to educe more than a small portion which should lie within the compass of merely written words. (16)
I lack words to express the full extent, or the earnest abandon of his persuasion. (20)
It’s almost like he’s trying to make a point here. Poe renders his story even more horrifying, even more bizarre, by claiming that it’s even scarier and crazier than it sounds in his story. Whatever the narrator says was going on, take his word for it – what actually went down was worse.
You might want to think about the implications of this given that the narrator at one point reads aloud to Usher from a book and that the fictional sounds are manifested in reality. Here the narrator is insisting that words cannot describe reality… and yet the words he reads aloud to Usher come true! In fact, these fictional words he reads are prophetic. This is similar to the way that Usher predicts his own death early in the narrator’s tale. You might also want to think about the prophetic nature of narration in this text, given that Usher foretells his own death. We’ll talk about this more in Symbols, Imagery, Allegory.