What gets me as a non-native speaker far more than "a vs an" is the "a vs the" conundrum. I still don't quite get when something needs to be "indefinite" and I've been speaking English for close to forty years. My native tongue lacks articles altogether and it's soo bloody hard I feel hopeless I'll ever master them fully.
That rule isn’t universal though. “I go to the dentist every year” doesn’t imply that I particularly care about a specific dentist (or, case in point, about the specific dentist).
“This was a nice evening” is also difficult to characterize as not caring about which evening it is. As are books titled “An Introduction to XYZ”, where both the authors and the readers will probably care about the specific book.
This is because "a"/"an" mean "one". The stress generally is on it meaning "[any] one", but in your example "a" is used for its numerical meaning instead; the sentences "I have a son" and "I have one son" are interchangeable in this instance.
abraxas · · focus · HN ↗
AndrewDucker · · focus · HN ↗
"Pass me a plate" - any plate will do. "Pass me the plate" - I want the specific plate which we were talking about.
layer8 · · focus · HN ↗
“This was a nice evening” is also difficult to characterize as not caring about which evening it is. As are books titled “An Introduction to XYZ”, where both the authors and the readers will probably care about the specific book.
rawling · · focus · HN ↗
I'm going to a bank, a shop, a dentist - I've found a new one and I may well be about to describe it to you.
"A nice evening" - there have been ones before, there hopefully will be again, this was one of them.
mrheosuper · · focus · HN ↗
"I have the son" sounds odd, even if there is only 1 son on your mind.
archievillain · · focus · HN ↗