The Syntax of DP, IP, and CP in the Language of an Egyptian Down Syndrome Individual: A Generative Approach

Down Syndrome (DS) is a developmental disorder caused by a genetic chromosomal abnormality in the twenty-first chromosome that is characterized by poor cognitive and linguistic abilities. Several studies on the linguistic deviation in the DS population have reported deficits in the acquisition of language that persist from infancy until adulthood. However, most of the literature in this research area has been chiefly undertaken on English-speaking individuals. Hence, the current study endeavors to investigate the syntax of DP, IP, and CP in the language of an Egyptian DS individual within the theoretical framework of Generative Grammar. The rationale for selecting syntax and morphosyntax in DS for investigation is that it is one of the most affected areas by the intellectual disability caused by the syndrome. Thus, examination of the language disorder in an Arabic-speaking DS individual is expected to elucidate the linguistic characteristics of the syndrome further. The DS participant in this study came from a larger study investigating the phonological and syntactic impairments in a sample of Egyptian DS individuals. The primary objective of this study is to reveal the syntactic deviations in the participant’s language and compare them to the trends reported in the literature of typical language acquisition. The research hypothesizes that the syntactic errors are constrained by the rules of Universal Grammar. The analysis reveals the presence of syntactically operant functional heads in the underlying structure despite being phonetically null on the surface structure.