Children begin communicating from the moment they are born. Infants use other forms of vocalizing, such as cooing and babbling, to communicate with parents. Infants can alter the loudness, pitch and frequency of their sounds to express different moods.
Infants also use eye contact to form a bond with parents.
As an infant's understanding of his or her world grows, the infant finds that vocalizing sounds can be too limited to communicate about more complex ideas. Eventually, an infant begins to talk by imitating one of the thousands of words that he or she has heard since birth. A child's first word does not usually go unnoticed. An infant's first word is reinforced by parents' reactions. A child begins to develop a vocabulary of words which occur at the same time as an object or an event.