The child's acquisition of his native language is not dependent on any special tutoring. Parents may spend many hours "reinforcing" every bit of their child's verbal activity with a smile or some other reward. But there is no particular reason to believe that such activity affects the child's ultimate success in becoming a native speaker of his parents' language. Children can pick up a language by playing with other children who happen to speak it just as well as they can through the concentrated efforts of doting parents. All they seem to need is sufficient exposure to the language in question.