Source of Errors in English Headless Relative Clauses Produced by Persian Learners/Speakers of English

This paper focuses on errors made by Persian learners of English as a Foreign Language (EFL) when producing English headless relative clauses (RCs). Although English does not allow interrogative structure in headless RCs, Persian EFL learners tend to produce them in the interrogative form. In the course of the present research, potential sources of this error were explored, and eventually the Markedness Differential Hypothesis (MDH) showed to have more explanatory power, and made up the theoretical framework of the research. The oral and written corpus of the study was obtained in the course of two years through diverse sources from 137 female and male Iranian participants. The collected, naturally-occurring data yielded a pool of 126 ill-formed RCs, consisting of 85 (67.46%) ordinary headless, 25(19.84%) headed and 16 (12.69%) free headless RCs. Scrutiny into the data led to recognizing systematic errors in two main types (headless RC in subject or object position) and two subsidiary types (headless RC in subject position including copula verb) of English headless RCs. These systematic errors can be attributed to markedness differential hypothesis, not in the sense that the forms are different across the two languages, but because of the wider functionality of interrogative and declarative forms in English headless RCs, compared to Persian. This study calls for linguistic analysis of other facets of such systematic errors, more collaboration of linguists and language pedagogues to recognize and address learning problems, and studies on educational solutions for related problems.