If you know someone who can speak their mother tongue and your mother tongue, should you speak in their mother tongue? It is a tough question. If the person study our mother tongue as a foreign language, speaking in their language may spoil their motivation. On the other hand, if they try to speak their own language as if we should speak it, that may be rude and lack of respect of our culture.
I cannot find any good solution. If you find some language which you can communicate other, that would be a best choice while I do not want to deprive people of good occasions for various types of languages. If you do not permit people to use your language, that is like blaming imperfect of their language. You should pay attention to choosing language if you have choice.
Before consideration of language, you should pay attention to the extent of your friendship with people to talk with. You cannot communicate with people who never respect you. "No respect" is very radical situation. However, the amount of respect is one of the essence of good communications. You should decide your tactics based on relationships with others.
The answer depends on how you will communicate with others. If you do not expect to communicate someone, you are not necessary to worry choice of language. You should choose the best language for communication. You may use some language which the person are studying. That may also express your respect to them. The last thing you should do is scorn or ignoring people who are not good at your language. Learning language is not so easy. Moreover, communication require patience of each other.
