What does it mean when a 1985 VW Jetta has a hard time turning on? on 1990 Volkswagen Jetta

(I know I put 1990, but it IS a 1985. It would not let me go past 1990.) When the car is cold, it has some issues turning on for some reason. I don't know what it could be, I'm no car specialist. It's not the battery because that was already replaced. Any ideas?

Asked by for the 1990 Volkswagen Jetta
Starter maybe