The noun phrase accessibility hierarchy (NPAH) in the acquisition of English restrictive relative clauses by Turkish adult learners of English

While learning a language, the importance of the target language syntax cannot be denied. However, how this syntax is formed and developed in the learners' interlanguage has undergone many different explanations. Markedness is thought to play a role in learners' selection of syntactic items in the learning process; that is, it is claimed that students learn unmarked structures earlier and with a higher rate of accuracy than marked structures. This study aims at investigating this claim by studying Restrictive Relative Clauses in English within the framework of the Noun Phrase Accessibility Hierarchy (NPAH). It tries to find answers to three main questions: a) Do Turkish adult learners of English follow the NPAH while acquiring Restrictive Relative Clauses?, b) If not, what is the order of acquisition in Restrictive Relative Clauses for these learners?, and c) Do lower-intermediate and upper-intermediate students exhibit the same learning order while learning Restrictive Relative Clauses? To answer the research questions, 80 subjects (40 lower-intermediate and 40 upper-intermediate students) have been given three different tasks eliciting the five relative clause types on the NPAH. These included Grammaticality Judgement Test, Sentence Combining Task, and Translation Task. The findings suggest that the Genitive construction seems to violate the otherwise existing hierarchy, and thus neither of the groups follow the NPAH while learning English Restrictive Relative Clauses. Instead, the error rates refer to an order starting with Subject relativization, followed by Direct Object relativization, and Indirect Object or Oblique relativization.