How sophisticated is the grammar of this sentence from Edgar Allan Poe's story, The Tell-Tale Heart? Do you think that the author is well-educated?
"TRUE! --nervous --very, very dreadfully nervous I had been and am; but why WILL you say that I am mad?"
The first distinction we need to make here is one between the author, Edgar Allan Poe, who was a well-educated professional writer and impressive prose stylist and the anonymous narrator of the story. Thus our question becomes what Poe wanted to portray about the educational level and intellect of the narrator.
Before considering the first paragraph, examine the second paragraph:
It is impossible to say how first the idea entered my brain, but, once conceived, it haunted me day and night. Object there was none. Passion there was none. I loved the old man. He had never wronged me. He had never given me insult. For his gold I had no desire. I think it was his eye! Yes, it was this! One of his eyes resembled that of a vulture -- a pale blue eye with a film over it. Whenever it fell upon me my blood ran cold, and so by degrees, very gradually, I made up my mind to take the life of the old man, and thus rid myself of the eye for ever.
The final sentence is syntactically complex and grammatically correct and the diction is relatively sophisticated. Thus the broken language of the first paragraph is not intended to convey lack of education, but rather state of mind. Poe is attempting to convey the derangement of the narrator's mind by having him use the broken, almost incoherent language of someone under extreme stress. The second paragraph shows that the narrator, when in control of himself, is quite articulate, and thus emphasizes the degree to which he is going insane by contrast.
Thus we can say that the opening you quoted is a very sophisticated portrait of an insane narrator.
I think Poe is one of the most important American authors, which is certainly going to color my opinion of this quote. That said, I think you're looking at a stylistically sophisticated sentence that may not seem grammatically interesting.
I tend to equate this kind of style-shift with things like jazz music or modern painting for ease of understanding: Poe is using things that your English teacher or your SAT may frown upon, but he's doing so within a very specific (and advanced) parameter that keeps him from appearing amateur. That is to say -- Poe knows what he's doing and is utilizing (or ignoring) certain grammatical rules for emphasis within his story. In this case, your quote ("TRUE! --nervous --very, very dreadfully nervous I had been and am; but why WILL you say that I am mad?") is very jilted, jittery, and it mirrors your narrator's feelings.