When it comes to how your kid plays, it turns out that it’s not all just fun and games. According to sociologistMildred Parten Newhall, there are six distinctive stages of play from infancy until preschool—and each one offers an opportunity for your child to learn valuable lessons about herself and the world. Familiarizing yourself with these different types of play can help you feel at ease with your kid’s behavior (Hey, that train obsession is normal!) plus know how to better engage with him or her.