Comment by margalabargala
13 hours ago
Beyond that, there are cases where you absolutely are referring to a specific one, but use a/an.
"Our house has a pool" for example. There is a very specific pool being referred to, but it's sufficiently indirect that "the" would never be used here without radically changing sentence meaning.
I understand this mostly as "our house is one of a set of houses with pools", which is what anybody cares about in this sentence.
It's like saying "our house has a roof" — very similar, but nobody really cares about the roof, the focus remains on the house.
This doesn’t count because the determination of which house you mean is not based on previous context, but only on the sentence itself.