Although spoken English doesn't obey the rules of written language, a person who doesn't know the rules thoroughly is at a great disadvantage.

Know how to behave at a buffet. Take a clean plate for a second helping.

Attention-deficit disorders seem to abound in modern society, and we don't know the cause.

Be able to go shopping for a bathing suit and not become depressed afterward.

Know the official post office abbreviations for all 50 states without having to consult a list.

When you're in a good mood, bring up the past. When you're in a bad mood, stick to the present. And when you're not feeling emotional at all, it's time to talk about the future.

Know how and how much to tip people who expect gratuities, even in the case of poor service.