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

This study reports on the findings of error analysis of a learner corpus consisting of 238 English argumentative essays written by Korean college students, specifically on errors that stem from confusion of lexical categories. A three-step error analysis was conducted following a procedure established by Rod Ellis in 1995. The results revealed 10 commonly confused lexical category dyads—coordinators or subordinators mistaken for adverbs, adverbs for conjunctions, gerunds for nouns, the adverb almost for either an adjective or a noun, the pronoun each other for an adverb, adverbs for nouns, conjunctions for prepositions, prepositions for conjunctions, the preposition to for an infinitive, and the adverbial for example for a preposition. Discussions of the causes of such confusion—homogeneous L1 translation, failure to correctly punctuate spoken language in writing, lack of L2 grammar knowledge, negative transfer of L1 morphosyntactic properties, and lack of L2 lexical knowledge—are delineated with specific examples. The limitations of the study and pedagogical implications are addressed.