In order to test the hypothesis that the ability to form verbal concepts would increase with age, a test for verbal concept formation was developed and administered to 668 children between the ages of 4 and 9. By varying sentences that describe nonsense figures, 4 variables were systematically explored. (MS)

This paper describes the linguistic development of two hearing sons of deaf parents. Both were exposed to an early language environment different from that of the average hearing child. At the start of the study, the boys were aged 3 years, 9 months, and 1 year, 8 months, respectively. When first observed, the older child performed well below age…