Parents want their child to learn how to play. Then, they want their child to learn how to play with other children. This second accomplishment may be just a few skills away or it may be many skills and years away but, regardless, it is wise to remember that you are aiming in that direction.
Try to imagine what skills it will take for your child to play with another child. Then, little-by-little, help your child acquire each skill required.
Here is an example. At first, it is quite a challenge just to convince Darren to come and do any activity willingly with his mother. But over time, she prevailed. Mom had gradually convinced Darren to play more and more games with her and as I watched them play today, I realized that he has learned to play at least a dozen games. His favorite is puzzles.
Remember though, that we are aiming for Darren to not only play with Mom, but also to play with other kids--which he doesn't yet do. I could see how playing with other kids might be a challenge when Darren took a puzzle piece out of Mom's hand several times and she uttered nary a peep. She plays like a mature adult but in order to teach Darren the next skill (taking turns) she needs to play more like a kid. "Next time", I said, "don't let Darren take toys away from you." I explained the playing like a kid thing in a little more detail. She got the idea right away. They started another puzzle together and she said, "Darren, my turn first."