From childhood to old age, we all use language as a means of broadening our knowledge of ourselves and the world about us. When humans first 1 , they were like newborn children, unable to use this 2 tool. Yet once language developed, the possibilities for human kind‘s future 3 and cultural growth increased.

Many linguists believe that evolution is 4 for our ability to produce and use language. They 5 that our highly evolved brain provides us 6 an innate language ability not found in lower 7 . Proponents of this innateness theory say that our 8 for language is inborn, but that language itself develops gradually, 9 a function of the growth of the brain during childhood. Therefore there are critical 10 times for language development.