Three-year-olds are gradually learning to use pronouns such as “I,” “me,” “mine,” and “you.” Although they’re still struggling to comprehend where their bodies, possessions, and authorities end and someone else’s begin, they are beginning to understand that their parents and caregivers are separate people with individual feelings and needs.
Shelov, S. P. (Editor-in-Chief). (2004). Caring for Your Baby and Young Child: Birth to Age 5. The American Association of Pediatrics. Revised edition. New York: Bantam Books.