This study was conducted to find out the effectiveness of my writing instruction and prepare for the following writing instruction in a graduate school context in the Southern part of South Korea. To achieve the goal, three research questions were raised and answered in a given order; 1) Participants of the study (N=22) show progress in writing in terms of accuracy and fluency, 2) The most frequently appearing errors appeared in the post-test were Mechanics > Sentence types (Conjunction S+V, S+V) > Meaning > Mechanics (Title) > Usage. 3) In the pretest, Title > Paragraph indentation > Mechanics > Meaning > Balance errors appeared frequently. Error patterns between pre and post-test did not show idiosyncrasy. Based upon the findings of the study, instructional intervention, including writing, was suggested as the form of the quizzes in the future.