The present experimental study explores developmental characteristics of Korean EFL learners’ English negatives and yes-no interrogatives. Adopting the functional category acquisition framework within the UG theory, this study investigated 12 elementary and secondary school students’ interlanguage grammar by elicited production. The results showed that the learners’ interlanguage grammar developed gradually from VP to IP and CP structures in English negatives. However, their interlanguage grammar did not show gradual developmental tendency in yes-no interrogatives. The acquisition rate of negatives generally increased with the learners’ level whereas there existed individual variation in the acquisition rate and developmental aspect of yes-no interrogatives. This result suggests that CP structures instantiated by yes-no interrogatives seem to be acquired from the initial stage by some learners.

Abstract
Ⅰ. Introduction
Ⅱ. Theoretical Background
Ⅲ. Research Design
Ⅳ. Results and Discussion
Ⅴ. Conclusion and Suggestions for Future Research
References
저자소개

• Jung-Sun Shin(Cheonan University) | 신정선