This study inquires into the effectiveness of proactive approach to grammaring through explicit grammar instruction in developing linguistic accuracy of Korean EFL college students’ written products. Forty-eight students from two intact sections of mandatory English composition course participated in the experiment for 10 weeks. The control group was taught with traditional process writing methods, whereas a modified version of process writing pedagogy supplemented with two types of grammar instruction―15-minute in-class grammar lessons and individualized online grammar practice―were applied to the experimental group. Linguistic accuracy of the pre- and post-treatment essays was measured by obligatory occasion analysis in the use of subject-verb agreement, pronoun-antecedent agreement, the articles in front of count nouns, the present perfect tense, and passive construction. The statistical analyses show that the experimental group outperformed the control group in three of five grammatical categories. Variations in linguistic accuracy development over a 10-week period support earlier second language acquisition discoveries that some grammatical categories are more resistant to instructional treatment than others and that linguistic characteristic of the structures interact with individual learner’s cognitive maturity

• Sugene Kim(Ewha Womans University)