Joe Dinoffer has a great variation of the children's "tag" game for young kids learning tennis.
Now let's move to a great variation of the game Tag. In this game, three children hold hands in a circle facing in and one of those three children is designated as the target; the one who is supposed to be tagged. The child outside the circle tries to tag that designated youngster and the two children holding hands with the target child try to protect him or her from getting tagged. A good variation of this would be to have the children in the circle holding hands and facing outwards.