Language is a crucial means of gaining comprehension of Physics content as well as providing correct answers to Physics questions and explanations of Physics phenomena. Therefore language determines the academic achievement of Physics learners. Consequently, language diversity plays a pivotal role in the outcomes of education in a multicultural society such as South Africa. The research reports on the role played by language in the academic performance of learners whose language of instruction is different from their home language. A mixed method approach was used in which the participants were assigned to either the control or experimental group. Intervention was provided to the experimental group in form of Physics lessons in the learners’ home language. The mixed method approach was used to elicit responses from a sample of 40 learners on the role of language in the learning and teaching of Physics to learners whose home language is different from the language of learning and teaching. Data was collected from 3 written tests (an English Language Proficiency test, pre- and post- tests) and interview responses. The sample comprised 24 girls and 16 boys aged between 15 and 17 years. Quantitative data was analysed using R- computing while interview responses were analysed using Glᾰser and Laudel’s model. A paired t- test revealed statistically significant difference in the academic performance of the two groups in the post- test in favour of the experimental group which had been afforded intervention. The results of this study show that translanguaging approaches, where languages of input and output are deliberately interchanged, proved to be a valuable pedagogical strategy as learners got the chance to learn in their home language leading to an improvement in their academic performance in Physics. The findings of this research are in line with some previous research which demonstrated that the use of learners’ home language is a social practice that goes beyond the four walls of the classroom. The use of pedagogies that embrace multilingualism is therefore highly recommended in 21st century Physics classes. / Curriculum and Instructional Studies / D. Ed. (Didactics)