回复：my suggestions

It is very hard to serve balls for me. This is probably the most difficult
tennis skill to learn. I am afraid he might lose patient while I try to serve.

Right now, I just hit balls over, and he hit back. More or less like a tennis
machine. But don't have the intensity a machine provides. I probably should get a machine soon.


My son could hit against a wall. But the tennis wall here is in a basketball
court, most of the time there are people playing there. It is easier to get a tennis court than a tennis wall.

My son loves pretty much every sport as long as we let him play. So that is not a problem.