Persian Learners' Acquisition of Empty Categories in English Null Operator Structures

The study investigated the acquisition of empty categories in the English complex infinitival structures. A quasi-experimental design was used in which four groups of Persian learners of English (elementary, lower intermediate, upper intermediate and advanced) via convenient sampling were selected and assigned into different proficiency levels using Oxford Quick Placement Test. Then, the groups were given three tasks, a translation task, a picture-cued sentence completion task, and an error-correction task to see whether they learn the feature of nonfiniteness which is absent in Persian and if so, at what level Persian speakers learn English null categories. The study specifically tries to find whether optionality in the use of clitics in null operator structures appear in developing English interlanguage of Persian second language learners. As the findings of the study revealed, it seems that, after a short period of L1 transfer, Persian learners of English learn nonfiniteness quite rapidly while clitic optionality in null operator structures is observed in their performance , however, as their level increases, the this optionality in the use of pronominal clitics fades away.