The present paper summarizes three experiments that investigate the effects of age of acquisition on first-language (L1) acquisition in relation to second-language (L2) outcome. The experiments use the unique acquisition situations of childhood deafness and sign language. The key factors controlled across the studies are age of L1 acquisition, the…

A total of 1,018 signs in one deaf child's naturalistic interaction with her deaf mother, between the ages of 19 and 24 months were analyzed. This study summarizes regular modification processes in the phonology of the child sign's handshape, location, movement, and prosody. First, changes to signs were explained by the notion of phonological…

Examined longitudinally the handshape aspect of American Sign Language signs in young children of deaf parents. Parents demonstrated on videotape how the children formed the different signs. Findings reveal that four basic handshapes predominated in early sign production, and that the part of the hand involved in contacting a sign's location often…