1Islamic Azad University, Science and Research Branch, Tehran, Iran
2English Dept. of Iran University of Science and Technology
The benefits of textual input enhancement in the acquisition of linguistic forms have produced mixed results in SLA literature. The present study investigates the effects of textual enhancement on adult foreign language intake of two English linguistic forms-subjunctive mood and inversion structures-to explore the role of the type of linguistic items in input enhancement studies. It also investigates learners’ trend of development in the acquisition process of these structures. Thirty first year college-level participants were exposed to twelve enhanced texts for subjunctive mood and twelve other texts for inversion structures. The study employed a pretest-posttest-delayed posttest design to explore the effectiveness of instructional treatment in the short term and long term acquisition of the structures. Alongside a pretest and a posttest, three production tests were administered to assess the trend of development in each structure.The results revealed that textual enhancement aided the learning of the target forms. With regard to type of linguistic items, significant benefits of subjunctive mood over inversion structures were found during both short term and long term. This study revealed that textual input enhancement may have differential effects on the acquisition of linguistic forms. Theoretical, methodological, and pedagogical implications are also discussed.