Over the years of leaving in the U.S., I came across several terms that I had thought only exist in Chinese. However it seems at least in American English, there are same expressions. They are (and hopefully I would be keeping adding to this list):

• Going Number 1 and Number 2: growing up in China, I thought this was only my childhood “secret language” to tell which type of bathroom run you are going. But apparently, American kids have the same code language.
• Lose face: this has been discussed before somewhere else on the Internet.
• Pinky swear: Again, I thought this was only a unique swearing form used by Chinese kids. But obviously American kids use that too.