In this sentence, should I use the or a?
Mom: I think making a copy of this picture would be a good idea since your aunt wants a copy.
Me: Sure, I can make the copy.
Should I say "a copy" in order to make sense? Do I need to say "a copy" first and say "the copy" later in the conversation when referring to that copy? I'm not sure how early into the conversation I can start using the instead of a.
You can use either. Probably most speakers would tend to use the indefinite article ("a copy"). Not least because the preceding utterance used that form twice, and the definite article wouldn't really work for those earlier instances (it's plain invalid for the first, and awkward/highly unlikely for the second).
But there's nothing wrong with "I can make the copy", because by then we're in a context where we know which particular copy is being spoken of (it's the one the aunt wants, and hopefully is going to get).
