>>19
Well, take this for example: There are a lot of different languages spoken in India. 200 years ago this was no big deal, but today rural people around the world are flooding to the cities to get high-paying jobs, and international commerce usually needs English. If everyone needs to learn English so they can work at a call center (grossly oversimplified, but you get the idea), then they will also use English to converse with people who have different native languages. And then their kids won't need to know the native language at all.

>>21
It's easy! Just start a democratic revolution in China, and when they become an open and free society everyone will want to learn their language so they can make gobs of cash. You can help start the democratic revolution by working on Freenet so that Chinese college students will have access to open political discussions. Go on!