How do speech and language normally develop?

How do speech and language normally develop? The most intensive period of speech and language development is during the first three years of life, a period when the brain is developing and maturing. These skills appear to develop best in a world that is rich with sounds, sights, and consistent exposure to the speech and language of others. At the root of this development is the desire to communicate or interact with the world.

The beginning signs of communication occur in the first few days of life when an infant learns that a cry will bring food, comfort, and companionship. Newborns also begin to recognize important sounds such as the sound of their mother's voice. They begin to sort out the speech sounds (phonemes) or building blocks that compose the words of their language. Research has shown that by 6 months of age, most children recognize the basic sounds of their native language.

As the speech mechanism (jaw, lips, tongue, and throat) and voice mature, an infant is able to make controlled sound. This begins in the first few months of life with "cooing," a quiet, pleasant, repetitive vocalization. Usually by 6 months of age an infant babbles or produces repetitive syllables such as "ba, ba, ba" or "da, da, da." Babbling soon turns into a type of nonsense speech called jargon that often has the tone and cadence of human speech but does not contain real words. By the end of their first year, most children have mastered the ability to say a few simple words. Children are most likely unaware of the meaning of their first words, but soon learn the power of those words as others respond to them.

By 18 months of age most children can say 8 to 10 words and, by age 2, are putting words together in crude sentences such as "more milk." During this period children rapidly learn that words symbolize or represent objects, actions, and thoughts. At this age they also engage in representational or pretend play. At ages three, four, and five a child's vocabulary rapidly increases, and he or she begins to master the rules of language. These rules include the rules of phonology (speech sounds), morphology (word formation), syntax (sentence formation), semantics (word and sentence meaning), prosody (intonation and rhythm of speech), and pragmatics (effective use of language).