English-practice with native English speakers in China can be expensive. Chinese-practice with native Chinese speakers in China is easy to come by.
I'd say that the girls who put up advertisements for language exchange or teaching Chinese care more about finding a cheaper way to practice English than to find a foreign guy to sleep with: as this website has proven time and time again, you don't need to do anything half so complicated if you're a Chinese woman who is aiming to find foreign man to sleep with.
That's funny, if GIRLS offer Chinese lessons for free, what else do you think they want, Wayne? It takes two to tango.
When I was at school, I did help a friend from South Africa with Chinese, grammar, pronunciation... we have been friends for more than 5 years and still corresponding every now and then. I think everthing is simple, it's just we human beings like to make it complicated.
I too have had language exchanges that were platonic and quite useful. A few have since blossomed into great, lasting friendships and we still communicate quite regularly. I agree with Wayne though that you get what you pay for. While I have had a few useful exchanges most have been not too useful for learning language. By far the best thing one can do for learning language is to hire a qualified teacher with experience. You get out what you invest, if it is money or effort or whatever.
Hmm, mine was not language exchange though. It began as two persons having similar interest and I just offered my help, I didn't want to learn other languages at that time. I agree if one wants to do academic study, it's better to turn to professional for help or study on one's own. What I disagree here is one trying to guess what is in others mind which most of time is distorted by his own thought. Even if the free class is an excuse, it won't take a wise person long to know that unless he pretends to be a fool but enjoys it secretly.