Most parents can hardly wait for their baby to say its first word. This usually happens between the nine months and a year. From about two years, the child should be able to use simple phrases, and by three he should be able to use full sentences. By four, he should be fully able to talk, although he may still make grammatical errors. By five, he should have acquired basic language.

There is little doubt that language acquisition is one of the key milestones in early childhood development. Much of a child's future social and intellectual development hinges on this milestone. A language delay can lead to isolation and withdrawal, and to learning difficulties and poor academic performance. Recent research has revealed a dramatic link between the development of spoken language and written language among children, and the importance of language acquisition to basic reading skills.

Many parents believe that the term "language development" implies that the child