There are many tasks that are not intrinsically rewarding to us and we need to make it rewarding until the learner can see the value and reward in the task itself. At the end of your lessons you let the child show his mother and his mother praises the boy who enjoys pleasing his mother and then wants to do it over again. He now has a reason for swimming to the other end of the pool that is not directly related to getting something each time he does. You have to establish a chain of positive praise and reward, if you are to have the students maintain the behavior you desire. Like anyone, kids must see some reward to doing the tasks they are assigned.
Reward comes in many shapes and types.
Smiling, pats on the back, verbal praise, are some of the simple forms of reward that can be used that fosters a positive learning environment. Setting up goals on a chart and placing stars or stickers on the chart to show objectives completed. Giving certificates, etc. Each of these forms of reinforcement fosters a positive learning environment and helps the student learn new behaviors. When an undesirable behavior is exhibited you initially ignore it.