When you approach someone in a Chinese community, a game of chicken ensures. They hesitate to speak in English with you. Break the tension by approaching them first, in Chinese! Locals tend to be put at ease when they hear you make attempts to speak their language.
However, this also works well in western countries. If you overhear people speaking in Chinese on the street (it is best to confirm that they are indeed Chinese speakers first!), you can expect surprise, bewilderment and then encouragement (usually in that order) when you try speaking Chinese to them.
While it’s common to find westerners who speak Chinese in China, it’s very rare to find ones who do in western countries.
So show off what you know and stand out from the crowd!