This study explored the impact on learning Scientific and Mathematical concepts among English language learners, when the concept and its Specialist language is disaggregated. It has been assumed that students who learn to understand concept in General discourse (everyday terms) prior to being explicitly taught Science/ Mathematics Specialist Language will develop better understanding of concepts and content in general. Lesson plans were developed using the disaggregated approach to teach both Science and Mathematics in southern Philippines. The school respondents were chosen according to their type as private or public; location as urban or rural; level as elementary or high school. An experimental group and control group was assigned for each pair. Using the pre-posttest design, result indicated that students taught with the disaggregated approach significantly improved content understanding and linguistic competence compared to students taught in traditional ways.