OK, I think I get what Exapno Mapcase is saying. The “had done” isn’t meant to be “had felt” with “done” in place of "felt; it’s meant to be the past perfect tense of “did”.
So when Rowling says: “He felt more warmly than he had done” she is saying “He felt more warmly than he did” and perfecting the tense of “did”.
Whereas when I say: “He felt more warmly than he had [felt]” I’m saying “He felt more warmly than he felt” and perfecting the tense of the second “felt”.
So it’s not that the way that sounds natural to me is a different tense than the way Rowling writes it (they both have the second verb in the past perfect), it’s that we’re actually choosing different verbs.
So, I get how they both make grammatical sense. My main question, though is whether one is more of a British usage and one more of an American usage. I guess I have to think about why “had done” sounds strange to me. (And it sounds strange almost every time Rowling uses it – this is just one of many examples I’ve noticed.) It can’t just be that it’s past perfect, because my preferred construction, “had felt”, is also past perfect.
Let me think about when I would use “had done” vs. did . . .
I would say:
(1) “I ran more quickly today than I did yesterday.”
(2) “I ran more quickly today than I ever had [run] before.” (Rowling would probably say “had done” here.)
I’d probably only use “had done” in a sentence like:
(3) “I couldn’t believe what I had done.”
I think the difference is this: I’ll use “did” to substitute for another verb, but I won’t use “had done” to substitute for another verb. That is, in sentence (1) above, I could have said “I ran more quickly today than I ran yesterday”, but I substituted “did” for “ran”. In sentence (2) I won’t use “had done” in place of “had run”, although Rowling would. And it’s not because I avoid “had done” in general, since sentence (3) sounds totally natural to me. But in sentence (3), “had done” isn’t really taking the place of another verb.
So I guess my observation is this:
I think it sounds fine to replace simple past tense verbs with the past tense of “do”, but I think it sounds odd to replace past perfect verbs with the past perfect of “do”. In the latter case, I always leave the original verb, or just say “had” with the verb implied.
In the Harry Potter books, J.K. Rowling frequently replaces past perfect verbs with the past perfect of “do”.
My question is:
Is this a general difference between British and American English, or just a difference between Tim314 and J. K. Rowling?
It can’t just be about whether British speakers use the past perfect more, because I’m actually using the same tense as Rowling, I just refuse to replace my verb with a form of “do” when I’m in the past perfect tense.