I'm not a Tamilian and neither I'm from Chennai but it's entirely upto a person to talk in a language which he/she choses. It's not fair for anyone to impose their language or expect others to learn their language especially when you go to their place. Take for example,if you move to Germany do you ask them to speak in Hindi for your convenience ? No you learn the local language. Why should it be different in Tamil Nadu ? Just because someone somewhere said Hindi is a national language,doesnt mean everyone who doesnt speak the language should learn it.
