The way Anu feels Prerna's presence, then stops Kaushik and runs back to check whom he had collided with and then later gets shocked seeing Prerna’s name on the tag.... All this shows that Anu knows that Prerna is alive. Not only that, it shows the slight hope he is still having about Prerna, even when he doesn't want her back. And I think this is how CVs are going to reveal the past... By slowly giving hints one by one.