Several years ago, I took private English lessons from a beautiful Nepalese woman. The class took place once a week in a cofee shop and lasted three months. She came to Japan with her husband who took a doctor's course at Shimane University and she was an English teacher in Nepal.
The first thing she tought me was 'speak politely' It was really impressive for me and I think it's important for all language learners. People tend to want to speak casual way but it sounds rude sometime.
She went private schools in Nepal and learned all subjects in English. Of course local language were allowed in class at lower grade. To be continued, maybe.