WHAT TO DO IF VISA SITUATION CHANGES

For learning mandarin in China, you can simply apply for a tourist visa, or Student visa (if you are able to get official invitation letter from your school in China). Once you employed, you can change it within mainland China, generally through a visa agency. But keep in mind that their service is very expensive. Other option for you is to apply for a work visa in HK in person. The perocessing takes 4 working days, you can use rush and express service either if you need your visa within short time.