I want to know if all stories have to be written in past tense? Can I write one in present tense?
No they don't. You can write a story in any tense you like, as long as it makes sense. Many good writers have written short stories in the present tense.
And another question. I was just listening to Harry Potter and the half-blood prince audiobook(read by Jim Dale) and
hadnoticed that Mr. Dale had changed some parts of J.K. Rowling's original writing. He changed some past perfect tense parts into past tense.
(N.B.: this part is in reminiscence of a past event, I guess that's why Ms. Rowling wrote it in past perfect tense.)
Jim Dale's recording:
I wonder which one sounds better and smoother to you native English speakers? And are both versions grammatically acceptable? (in terms of tense)
Jim Dale's version sounds better on its own. But it's not possible to tell whether it's more correct grammatically without knowing the grammatical context of the surrounding sentences.
And would love to know more about tenses in story writing. Thanks:)