As English progressively becomes the global language, many native English speakers move to foreign countries to work as English teachers. However a review of the literature reveals that there is little research on their actual performance compared to the non-native local English teachers. This comparative case study examines pedagogic practices of native English speaking teachers (NESTs) and non-native English speaking teachers (NNESTs), and the impact of their teaching on English language learning as perceived by secondary students in Korea. The participants for this study were NESTs and NNESTs along with focal students who were each taught simultaneously by two teachers, a NEST and a NNEST. Six students and four teachers (one NEST and one NNEST and three students) participated at two separate middle schools in Korea. The primary data consisted of interviews with the teachers, classroom observations, audio and video-taped classes of the teachers, as well as interviews with the students reflecting how both the NESTs and NNESTs have impacted their English language skills. The major findings of this study were that due to the teacher-centered nature of the NEST's classes, the pressure to succeed on exams and the size of the class, the students were not able to develop critical English skills such as extended responses and general conversational skills. The students did note however, that their understanding of Western culture, as well as their listening skills, greatly improved in the NEST's class. One NNEST predominantly practiced the grammar-translation method geared to enhance students' test performances, while the other NNEST effectively used code-switching, L1 and L2, allowing students to participate in communicative activities. The study in the NNEST classes showed that in one NNEST class students were able to understand fully English grammar points and reading material which were essential to exam preparation. In the other class, while the exam preparation was not as intense, the teacher focused more on helping the students to think and to achieve a greater speaking ability. The results of this study suggests that local contextual factors which affect NESTs' and NNESTs' pedagogical practices must be more closely examined before enforcing the English-only rule. The study also indicates that there is a basic need to fundamentally correct the mismatch between test and pedagogy practice in English education in secondary Korean schools and to provide systematic support for the teachers. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.