美国人常用的一个表示Luck or Wish的手势！

Thanks for QuietSailor's pointing out my misunderstanding of this gesture.

1.An old superstition says that if you cross your fingers (usually two fingers of the same hand) it will bring good luck. Example: "I don't know what I will get for my birthday, but I am crossing my fingers that it will be a bicycle."

2.You cross your fingers when you try to make something happen by wishing that it will happen. A common saying: "Let's cross our fingers and hope for the best." Example: "Good luck on your test tomorrow. We'll be crossing our fingers for you!" Reply: "Thanks."

3.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. Example: "It would be great if our team won today, but don't cross your fingers." Example: "We are hoping that John will get accepted to medical school, but we are not crossing our fingers."

4.Another applicable situation is when you are telling a lie, you may cross your fingers and it's said that ,hopefully, you will be forgiven for lying. Hehe, sounds like a self-deceiving .