We use the past after wish. We use wish to say that we regret something, that something is not as we would like it to be: I wish I knew Paul's phone number. (=I don't know it and I regret this) It rains a lot here. I wish it didn't rain so…

If I do ... Lisa has lost her watch. She tells Sue: Lisa: I've lost my watch. Have you seen it anywhere? Sue: No, but if I find it, I'll tell you. In this example, Sue feels there is a real possibility that she will find the watch. So she …