I am just confused about how to use have/has had
- David has had a nice car.
- David had a nice car.
May I know which sentence is correct and why, and please let me know how to use have/has had.
David had a nice car means simply that, at the time of which we are speaking, he was in possession of that car. That would be a natural thing to say.
If we were to say David has had the measles, it would mean that he has, in the past, caught that illness (but he may have long since recovered).
So we might say David has had nice cars [in the past], but I don't think much of his present one.
"He has had a nice car" is normally interpreted as an experiential perfect.
The event or state is expressed as an experience which happened at least once, without respect to a particular location in time, and which is repeatable. (SIL Glossary).
We use the past tense when the proposition expressed is no longer true in the present, so "He had a nice car" means he had a nice a car in the past but not now. He probably has a badly-maintained car or no car whatsoever.
