"How are you" is a good question. It’s a friendly way
to greet each other. But "How are you" is also a usual question. It is a
question, but it doesn’t often need an answer. When a person asks "How are you"
he expects (期待) to hear the answer "Fine"，even if (即使) the person’s friend isn’t
fine. That is because "How are you" isn’t really a question. But "Fine" is
really an answer. They are just like "Hello" and "Hi". After
people finish their talks, they usually don’t say exactly what they are
thinking. For example, when one person says, "I have to go now." The person
often doesn’t want to talk, so he gives an excuse. The excuse may be real, or it
may be not. But it isn’t polite (礼貌) to say that he doesn’t want to talk.
The excuse is more polite, and it doesn’t hurt the other person’s feelings. It’s
an important way for people to be friendly to each other. "How are you" is not like "Hello" and "Hi".