Mandarin is one of the preferred languages to learn especially for people who wish to settle down in Asia for business. However it is not a language you can always learn without structured methods of instructions. I have discovered many natives who struggled to remember key phrases even after learning the language from native speakers. The system of instruction used to teach English speaking students the Mandarin language has to take into consideration the natural learning habits English speakers have, and therefore, the approach to teaching is also not the same.
Suppose you can now learn from an experienced trainer who has more than 40 years of experience speaking in non-native languages, would you be interested? Suppose you do not have to leave your house to do these lessons, pay thousands of dollars on language courses to become confident with speaking Mandarin (and perhaps English), would you be interested?