It is not realistic to make Putonghua compulsory for teachers and students in Hong Kong. As Hong Kong has been a colony of British, most people in Hong Kong are native English or Cantonese speakers. They are not familiar to Putonghua.
In 1980s, Putonghua was not a compulsory subject for students. At that time, Putonghua was not important at all. In early 1990s, Putonghua has been made compulsory for all students, in order to prepare for the return of Hong Kong to China. …
