This action research explores how teachers and students at a private elementary school in Gyeonggi Province perceive the effectiveness of the English-only TEE policy and proposes a revised model tailored to the school's diverse needs. A total of 250 students and 6 teachers participated in the study, with data collected through surveys, interviews, class observations, and student logs. Frequency analysis and an inductive approach to qualitative coding were used for analysis. The findings indicate that most students and teachers favor a balanced approach, incorporating both English and Korean in the classroom. Students preferred using a mix of English (60-80%) and Korean (20-40%), emphasizing that engaging activities, such as games and videos, significantly enhance comprehension and engagement. Teachers found Korean helpful in explaining difficult vocabulary, providing instructions, and managing classroom discipline, especially for low-level students. The study proposes an "English-only policy with exceptions," integrating strategic Korean use to clarify complex concepts, scaffold learning, and foster a supportive environment. This approach aims to maximize student motivation and confidence while still maintaining English as the primary language of instruction.