This study was conducted to determine the effectiveness of my writing instruction and prepare for the following writing instruction in a university context in Southern South Korea. To achieve the goal, three research questions were raised and answered in a given order; 1) Participants of the study show progress in writing in terms of accuracy and fluency, 2) The most frequently appearing errors in the pretest were Meaning > Paralleism > Thesis statement > Conjunction S+V, S+V > Connectives, and 3) Meaning > Sentence types (S+V) > Logic > Mechanics > Agreement (Noun numbers) errors were survived at the end of the semester. Compared to the previous teaching context, my new students at a new university, called P University, show unique ways of making writing errors. What makes this discrepancy? Based upon the findings of the study, instructional intervention including writing was suggested as the form of the quizzes.