Hello, it's very nice to meet you. I come from Shanghai and graduated from Shanghai University, studying computer science. Mandarin Chinese is my native language. I've been worked in Pittsburgh (PA,USA) for one year. I can speak English pretty well. I taught computer programming in senior high school when I was in university. So I'll be patient to help you with your Mandarin Chinese. You are very welcomed to chat with me.
P.S. I can speak Shanghainese as well. I can teach you if you are interested in this dialect.