The acquisition of classifiers in verbs of motion and verbs of location in Brazilian Sign Language

This dissertation explores the relationship between the language model to which children are exposed and their resulting language acquisition. Bickerton (1981) and others claim that children can become proficient in a language even when they are exposed only to non-proficient speakers. It is not clear whether a particular threshold of proficiency in the input is required for complete acquisition in the child. The acquisition of Brazilian Sign Language (LSB) is an ideal testing ground to assess the limits of Bickerton's claim. Most Deaf children in Brazil are born to hearing parents and learn LSB at schools from teachers who are not proficient signers. This dissertation explores the effect of the variation of proficiency of LSB input on the acquisition of one linguistic structure, in 61 children aged 4:6 to 11:10. Two other variables are examined as controls: length of exposure to LSB, and chronological age.; The structure under study is the classifier. In signed languages, classifiers are used with verbs to indicate properties of the Theme including visual-geometric characteristics, abstract semantic category, and instrumental function. This study assesses the effect of the earlier-mentioned variables on the age of onset of production of classifier handshapes, the relative difficulty of production of different handshapes, and errors produced indicating the sequence of classifier acquisition.; Results show that even children with highly impoverished input attain some proficiency and provide partial evidence for Bickerton's hypothesis. Children selected similar handshapes to represent objects, regardless of a plethora of choices based on object form, and regardless of degree of fluency in the input. Deaf children also consistently categorized the objects differently; using handshape, while hearing children organized these objects using other properties. The quality of input also creates differences; for example, children exposed to more proficient input were more consistent in demonstrating handshape orientation in space.; Although exposure to non-fluent speakers is not a sufficient condition for internalizing the parameters of language resulting in fluency, and increasing exposure to skilled language models helps improve language skills, children with impoverished input show consistent patterns in their acquisition providing evidence for some innate cognitive process underlying language learning.