International communication
International communication is not a simple thing. In my opinion, even if you speak fluently and have perfect pronunciation and grammar it may turns out that is not enough. You need to have a better understanding what culture is and how to interact with representatives of different nations and countries.
When you look at someone your first impression is based on the clothes and appearance of a person, on language he or she speaks, but it's only a small part of whole his or her culture. You should go deeper in people's values, thought patterns and beliefs that represent their internal culture to understand it properly, because, for example the same term in different countries can mean different things.
At the same time if you ask two persons from one culture about definite things that describe their nation, you can get two absolutely different answers and it will be fine. So the concept of culture of other people is quite vague and your notion about it will depend on your educational background, language knowledge or how familiar you are with the geographical context and government system of the country. Also, if you have ever been to this country, it, of course, will help you in communication with its natives.
The last but not least thing is that we must not to resort to stereotypes because it may destroy our possible communication or it will create the wrong notion of other cultures.What we should really do is to keep open mind, ask questions without fear of misunderstanding and be fully aware of our own cultural traditions and beliefs.