Can, lah!

I have to comment on two phrases I hear often here that crack me up. The first is, "Can!" in response to any question. Not, "Yes, you can" or even, "You can," but just "Can!" I suspect this is because in Chinese, you will hear, "Keyi" (kuh- yee) a lot, which literally translated is just "ok" or "can." Since a lot of people here also speak Chinese, it comes out just "can."
"Can I use my ATM card here?"
"Can!"

The other phrase that I don't quite know how to employ myself yet is "lah." You'll hear it at the end of a phrase, such as the woman at IKEA last week who shouted at her kids, "Stop fighting lah!" Or my friend's doctor, when she was in labor and asking for more drugs who said, "I'm giving as fast as safely can lah!" It must be for emphasis. I don't care - I want to use it! Can I? Can lah!