I think I'm having trouble of understanding "here is/are" sentences. Some of them are OK but some of them are not clearly comprehensible to me. For instance:

The woman spoke with a heavy western North Carolina accent, which I used to discredit her authority. Here was a person for whom the word pen had two syllables. Her people undoubtedly drank from clay jugs and hollered for Paw when the vittles were ready -- so who was she to advise me on anything?

Is it OK to say "This was a person" instead of "Here was" in this context? If so, is there any difference between them?

Thank you,
No, you can't do that. You can say "She was a person..." but that has a slightly different meaning than the original utterance.

"Here is/are" is used to introduce a subject, that is something that you're going to talk about.
OK, thank you for the reply. I think I should read the sentence over again. I could sense the meaning of "here is/are" but can't translate it beautifully.