Babies communicate through sounds, eye gaze, body movement, crying and smiling. As they grow, they learn to understand language by listening to and watching others. Through back-and-forth interactions and play with others, your child expands her ability to express herself using gestures, sounds, and then words. Your toddler’s expressive communication skills develop gradually into speech, as he learns to make specific sounds and sound combinations by imitating the speech and language of those around him.