All social groups have preferred ways of speaking. For instance, contemporary English greetings include hi, what’s up?, how’s it going?, how are you?, hello, how do you do? and g’day (for many Australian English speakers, at least!). Furthermore, social groups tend to have preferred ways of speaking for particular contexts. For example, how do you do? would be highly valued at a formal occasion but it would not be a good way to greet your friend in the morning. You would need something cooler, more humorous – even perhaps a loud groan!
Most languages have differing styles of communication according to:
levels of familiarity (e.g. family, friends, acquaintances, strangers)
levels of formality (e.g. extremely formal to informal)
types of situations (e.g. professional, business, sport, private, public)
Getting these levels correct is often called socially appropriate behaviour or politeness.
Not surprisingly, politeness formulas vary across cultures. For instance, Chinese and Indonesian speakers often greet one another by asking where are you going? or have you eaten? Individuals from Anglo-European cultures can find these questions invasive, not recognising them as mere formulaic greetings akin to how are you? In other words, a Chinese or Indonesian stranger may not care where you are going any more than an English stranger cares about your general state of being. Moreover, a lengthy explanation of the day’s eating and travel plans would be as inappropriate in China or Indonesia as a discussion of your physical or mental ailments would be in Australia, the United States or the United Kingdom.