Theoretically based hypotheses of deaf learners’ written productions
As we remarked previously, only few authors have addressed deaf learners’ development of the oral language in the light of the theoretically based hypotheses of language development discussed in section 2.2. Berent’s studies (Berent 1996) are a remarkable exception. This author reinterpreted the results obtained in a broad project, in which deaf students’ development of English was assessed through a standardised test (the Test of Syntactic Abilities, TSA), against the backdrop of Radford’s VP hypothesis (see section 2.2.2). According to Berent (1996: 489), the results obtained in that study suggest that “deaf learners’ acquisition of English syntax follows a developmental pattern in which thematic categories are acquired before functional categories and that, for many deaf learners, the functional categories resist acquisition indefinitely”.
At the same time, Berent (1996: 490) argues that a straightforward interpretation of deaf learners’ data is difficult not only because of the variety of methods used to collect them and the diversity of participants’ profiles. This author (1996: 490) also remarks on the circumstance that deaf learners are taught the oral language as “a system of rules to be learned consciously”, similar to the way foreign languages are taught to hearing learners. Berent speculates on the possibility that learners’ skills might reflect both naturally and consciously acquired structures. He argues that the available data are interpretable within the theoretical framework of generative grammar. Based on the data analysed, he proposes that deaf learners’ learner grammars of English are best described as VP grammars as they are characterised by a lack of FCs. Learners produce SVO sentence patterns. Question formation is not mastered; neither are subordination nor verb tense and agreement marking. The copula is often omitted. Berent also remarks on the confusion of the auxiliaries be and have. Further, Berent (1996: 492) argues that the rare use of articles and pronouns reflects the lack of the DP level. The overuse observed in learners that start to use articles is assumed to be an effect of formal instruction in the language, whereby learners develop a metalinguistic awareness about this class of words but do not acquire the grammatical category they relate to.
As pointed out by Berent, many learners remain at the VP stage for many years. For those who expand this structure he maintains that they do so in a stepwise fashion. As some target structures seem to be acquired before others, Berent (1996: 501) argues that deaf learners expand their learner grammars progressively: “Thus, with respect to the successful acquisition of English phrase structure, there is evidence that deaf learners’ clauses grow, bottom up, from VP to IP to CP, each successive stage leading to a larger language.” Notice that this view differs from Radford’s original proposal that all FCs would become available at a time, but patterns well with the structure-building hypothesis portrayed in section 2.2.2.