Isn't it supposed to be either ''den gamla tidningen'' or ''en tidning ar gammal''? I don't understand why the indefinite form of the adjective is used here, while ''tidningen'' = the newspaper. It would be amazing if someone could explain this!
It only happens when the adjective stand before the noun (in technical terms attributively) and not when it stands after the verb here (predicatively). So you’d indeed say ”Den gamla tidningen” but you cannot say ”Tidningen är gamla.”
New to this but I believe so. There are other questions in this section which refer to grandparents being old. Min farfar är gammal... or similar.