Cross Your Fingers = hoping it happens that way we want
->An old superstition says that if you cross your fingers (usually two fingers of the same hand) it will bring good luck.
->You cross your fingers when you try to make something happen by wishing that it will happen.
->The meaning of don't cross your fingers changes a bit. It means don't hope too much for what you want to happen, because there is a strong chance that it might not happen. It means that you should not have expectations that are too high.
1. I don't know what I will get for my birthday, but I am crossing my fingers that it will be a bicycle.
2. A common saying: "Let's cross our fingers and hope for the best."
3. Good luck on your test tomorrow. We'll be crossing our fingers for you!
4. It would be great if our team won today, but don't cross your fingers.
5. We are hoping that John will get accepted to medical school, but we are not crossing our fingers.