One of the best ways to get to know someone is to just say hello. This may seem like a usual method（ 方 式 ）,1 saying hello to someone is different from country to country, and even from area to area in the same country. In the United States, people2 other people informally（非正式地）for the most part. Saying hello tells you a lot about the person you are3 , and it also tells that person something about you. Typical greetings are "hello, good day, good morning, good afternoon or good evening". All of these greetings can be4 informal greetings that are commonly understood in the United States.
Some of the more informal greetings have been changed greatly from person to person. Younger people have created their own slang（ 俚 语 ）for greeting5 and the slang is constantly changing. For example, the greeting "what's happening" was very6 during the 1970s and 1980s, and it is still in use today, but it has been replaced（ 代 替 ）by several other greetings by the younger. "What's up" can be often heard in the US among7 people. These two greetings are considered informal greetings that a person should8 use in a formal setting. These are usually used for informal en- counters（相遇）and are usually said among friends.
When a person says9 to another person, it says a lot about that person. It shows a friendly attitude and the willingness to get to know the other person. It can mean that the person starting the 10 is someone who is outgoing. If the greeting is accompanied（伴随）by a smile, it is all the better.
