1) cross your fingers 两指交叉以求好运
I have a big interview tomorrow! Cross your fingers for me!
Make a basket! Make a basket! Yay he did it!
2) wrapped around one's finger 能够很容易地影响别人
That little girl has her dad wrapped around her little finger. He buys her any toy she wants!
3) green thumb 某人在种花或种菜方面很有才能
My mom has a huge green thumb! She grows a huge garden every summer!
4) I can't put my finger on it. 我弄不清到底是什么
This coffee has a very interesting flavor! But I can't put my finger on what it is. I think it's vanilla!