| This article is intended to present the result of a research conducted by a team of researchers*) in an SMA in Bandung Indonesia to ascertain the effectiveness of the use of quality pedagogic language in improving students’ achievement in English. For that purpose, an experiment has been done in a first grade class. Using a quasi-experimental design, the class has been taught using the language thus far used by the teacher in the first six meetings, and using the quality pedagogic language in the following six meetings. Prior to the first meetings, a pre-test was conducted to ascertain students’ learning achivement before the treatment. Then, a post-test was conducted at the end of the experiment. The result of the data analysis showed that there was a significant difference between the pre-test and post-test means in the English competence, and no difference in those of their effective factors. Possible explanations to these unlinear patterns of findings have been presented and relevant recommendations have been given both for thearetical and practical aspects of English teaching, especially in schooling system. |