One study shows that Americans prefer to answer with a brief 'Yes', 'No', 'Sure', or the very popular 'Yeah' rather than with a longer reply. But brief replies do not mean Americans are impolite or unfriendly to some extent. Very often, Americans are in a hurry and may greet you with a single word 'Hi', indeed this is a greeting you will hear again and again during your stay in the United States. It is used by everyone, regardless of rank, age or occupation. However, those who are accustomed to longer greetings may re- quire a little more time before they feel comfortable with American simple talk. Americans sometimes use plain talk when they are uncomfortable. If people praise them or thank them in an especially polite way, they may become uncomfortable and not know what to say in reply. They don't want to be impolite or rude, you can be sure that they liked what was said about them. Except for certain holidays, such as Christmas, Americans don't usually give gifts. Thus, you will find Americans embarrassed as they accept gifts, especially if they have nothing to give in return. They are generally a warm but informal people. The fact that Americans like shorter answers tells us______.