QuickStart for 7-8 Year Olds: Four Square
This popular playground game can be adapted for tennis. This can be played over the net using the four service courts of the 36-foot court. Each service court is numbered one through four and players enter the court in square one. All points begin in the Ace Square, square four. The player in square four starts the ball with a drop and hit into any of the other three squares.
The player in that square must hit the ball before it bounces twice. If the player hits it out of any of the squares, or if it bounces twice before they hit it, they are out and everyone move up to that vacant square and a new player enters on square one. The game can be played without racquets by tossing and catching a larger ball.