English people like to say "Thank you" when others help them or say something kind to them. In fact, people all around the world do so. It's a very good habit. You should say "thank you" when someone passes you the salt on the table or opens the door for you, or say you have done your homework well.  "Thank you" is used not only between friends but also between parents and children, brothers and sisters, husbands and wives. "Excuse me" is another useful short expression. When you hear someone say so behind you, you know he or she wants to walk past you without touching you. It's not polite   to interrupt  others when they are talking. So if you want to speak to one of them, say "Excuse me" first. You should also do so when you want to make any noises  that may trouble others or you have to leave early at a party. Let's all learn to say "Thank you" and "Excuse me". It's really important to get into the good habit. If you want to walk past someone without touching him, you'd better say "  _  " first.
Hello How do you do Excuse me Don't move