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…

We tested the hypothesis that syntactic and narrative comprehension of a natural sign language can serve as the linguistic basis for skilled reading. Thirty-one adults who were deaf from birth and used American Sign Language (ASL) were classified as skilled or less skilled readers using an eighth-grade criterion. Proficiency with ASL syntax, and…

Examines whether manually coded English (MCE) sign language systems are learnable. Reading achievement and expressive English skills of deaf students educated using only a MCE sign system were examined. Deaf students had expressive English skills comparable to hearing students in respect to syntactical and lexical skills but were deficient in…

Examines the effect of adult recasting in sign language on the acquisition of specific syntactic-semantic structures by deaf children aged 9 to 76 months. Results indicated that recasting triggered the acquisition of new syntactic-semantic structures in American Sign Language and English, evident in the spontaneous production of previously…