The Strong provides a resource for scholars looking for definitions of play through the Museum’s Elements of Play chart.
“Play is difficult to define because it is complex. Many scholars find that describing play is easier than defining it. To help advance discourse around a definition of play, research undertaken at The Strong suggests that six basic elements—anticipation, surprise, pleasure, understanding, strength, and poise—are present each time someone plays fully.”
For further information about the role of adults in children’s play, check out this scholarly journal article about the connection between language development and play:
Weisberg, Deena Skolnick, Jennifer M. Zosh, Kathy Hirsh-Pasek, and Roberta Michnick Golinkoff. “Talking It Up: Play, Language Development, and the Role of Adult Support.” American Journal of Play 6.1 (2013): 39-54.