Why do I have to say please and thank you?

"Please" and "thank you" are both often referred to as "the magic words," and there are lots of reasons why saying these things is so important.

Both terms are polite ways of showing someone that you appreciate something they've done for you.

If you'd like someone to hold the door open for you, saying "Hold the door!" sounds like a rough demand, while saying "Please hold the door" makes the same thing into a polite request! Saying "thank you" does the same thing. If someone helped you look for a lost button or bought you a present, saying "thank you" shows that person that you appreciate the time and thought they have given you in helping to look for the lost button or buying you a present!