The study aims to verify the impact exerted by task-oriented and relationship-oriented teaching styles adopted by English teachers on the cognitive, motivational, and behavioral proficiencies of elementary school students learning English. To this end, online questionnaires with questions about the English teachers’ teaching styles as well as their own English learning competencies were distributed and collected from after-school programs of public schools and private educational institutions and 262 students in grades 4 to 6 across six provinces in Korea. The major findings are as follows: First, both task-oriented and relationship-oriented styles influenced students’ learning competencies significantly. However, the impact of the task-oriented teaching style was relatively stronger on cognitive competence than that of the relationship-oriented style. Next, the relationship-oriented style significantly influenced motivational and behavioral competence, while the task-oriented style had none. Therefore, this study suggests that English teachers should exercise a relationship-oriented teaching style to enhance students’ English learning competencies. However, teachers should prioritize task-oriented teaching for students who lack cognitive competence. Moreover, to effectively demonstrate teaching styles, teachers should adapt their instructional approaches based on the educational situations at hand and the individual characteristics of their students.