Registers, Styles, and Dialects!

As book says multilingual countries such as Switzerland, Belgium, and India, different languages are spoken by different group of people. Similarly My country Nepal also has hundred of different tribal languages allocated to specific social situation. But still language choice is not arbitrary thus people speak the language according to the importance of different context. Though different tribe have different languages, still they are compel to use Nepali as their national language and English as the most essential foreign language.People can't survive in academic context of Nepal till they can't speak these two Nepali and English language though they have their own tribal language.Thus they should choose these languages consciously or unconsciously to survive in the academic context.