You also learn a lot of rules. You learn what kind of greeting to use in different situations.For example, in English, we use formal and informal greetings.In china, a traditional greeting is " Have you eaten today?" In addition, there are rules for making small talk when you meet a person. Once you have learned the rules of a language, you can communicate more easili and avoid misunderstandings.
People in different cultures also have different ways of using their bodies to communicate. We use our heads and our hands to make gestures, for example. But there's one kind of communication that's the same everywhere. Asmile can always connect people.