We usually think of play as something that's done only in one's free time, separate from the serious business of life.
For an infant or a toddler, learning to play is a crucial part of social development.
The ages between eight months and three years are a very busy time for children. This is when they first learn to use language, starting with single words and moving gradually into word groups and finally sentences.
This is also when they learn what psychologists call symbolic play; that is, using gestures or objects to symbolize other events and objects. Just as the abstract words of a language can symbolize real things the word "house" for a real house a child's play doll might come to symbolize a real baby.
What's more, just as language starts with words, then moves gradually to sentences, symbolic play starts with discrete episodes pretending to change the baby, pretending to answer the phone then moves to more elaborate games.
The Important Connection
A number of psychologists have studied the connection between play and language mastery. One group found that they could predict how quickly children would learn to speak by carefully watching how they played.
Another study seems to indicate that you can actually improve a child's mastery of language by training him or her in the basics of symbolic play, although more research is needed to confirm this.