Language development is one of the most important parameters of cognitive
and emotional development. In infancy, language development is categorized as prespeech (birth-10 months); at this time, the skills needed to understand
language (receptive) are acquired by learning to localize sound. Expressive skills begin with cooing (vowel sounds) and differentiated crying when the baby is hungry, hurt, or in need of attention. At 3 months, babies begin vocalizing when they see an adult, and at 5 months, they take turns vocalizing with adults, quieting when the other speaks, and mimicking tone changes, although not actual words. At 6 months, babies add consonants (babbling), and when their parents respond to “mama” and “dada” with smiles and hugs, the baby eventually connects meaning to those sounds. When babies attach meaning to gestures or vocalizations, they have developed true
words and initiated the naming period (10-18 months). Usually, “mama,” “dada,” the infant’s name, and “no” are the first recognized labels. Once begun, the growth of receptive language is rapid, and by 12 months, 100 words may be understood. One-step commands associated with a gesture can be understood by the child at 1 year of age, and the need for a gesture is lost in a few months. The development of expressive skills progresses more slowly, with most children having at least one true
word before their first birthday and most of their verbalization consisting of complicated multisyllabic consonant and vowel sounds with intonation changes, called
jargon. By the end of the naming period, 18-month-old children use approximately 25 meaningful words spontaneously.