The one that gets me is when people use "a" with initialisms, e.g. "She drives a RV," just sounds off to me. she can do her thing but I drive an RV.

That said, I think the former might be more common these days, so arguably the rules might just differ between written an spoken English in some dialects.

But I bet she drives a Recreational Vehicle instead of an Recreational Vehicle.

When people get this wrong, ask them to spell it out phonetically. We sometimes forget that our language is more based on sound than sight.

An arrvee.