I would encourage the student to go to a good Chinese school. Be a diligent student. Listen to the pronunciation carefully. Visit free web sites. Find good dictionaries, watch Chinese TV or listen to Chinese radio. Expose to Chinese as much as possible.
This reminds me of my niece and nephew. Both of them are fluent in English and Chinese and they are 3 and 6 years old (at the time this was written) respectfully. They cannot write Chinese, but they can speak Chinese fluently. They made mistakes and asked a lot of question of how to say this and that. They are not shy when we laugh at their mistakes. So, try learning like a child with an open mind. It is not too difficulty, you just need practice.