answer: Kathy teaches #Person1# that tennis can be played singles or doubles and they use coins to decide who starts serving. She also introduces the scoring rules.
documents: #Person1#: Kathy, it seems you're having a lot of fun playing tennis.
  #Person2#: Would you like to learn?
  #Person1#: Yes, how do you play?
  #Person2#: Tennis can be played in singles or doubles. Look, there, the outside lines are for doubles and the inside lines are for singles.
  #Person1#: How do you decide who start serving?
  #Person2#: Well, you can use a coin to decide. Whoever wins chooses either to serve or the side of the court.
  #Person1#: How do you count the score?
  #Person2#: At the beginning, the score would be love.
  #Person1#: Love means 0?
  #Person2#: You got it, it is then counted to 15, 30 and 40. If you get to 40 and win again, you win the game.
  #Person1#: The other side start serving then?
  #Person2#: Right, see? You know how to play now.