In the US, people prefer waiting for a table to sitting with people they don't know. If you are sitting at a table with people you don't know, it's impolite to smoke without first asking if it will disturb them.
At American restaurants and coffee shops, you are usually served cold water before you order. You may find the butter and bread is free. And if you order coffee, you may get a free refill(续杯）.
Most cities and towns have no rules about opening and closing times for stores or restaurants. In large cities, stores may be open 24 hours a day.
Servings in restaurants are often large, too large for many people. If you can't finish your meal but would like to have the food later, ask your waiter or waitress for a "doggie bag", it may have a picture of a dog on it, but everybody knows you're taking the food for yourself.
Supper and dinner are both words for the evening meal. Some people have "Sunday dinner". This is a big noon meal.
