Internationally English is increasingly being used as a language of instruction in education. This is also true within the South African context, a country with eleven official languages. Many non-native English speaking (NNES) students, for whom English might be their second, third or even fourth language, are studying through the medium of English. Previous studies on this topic acknowledge that the level of English proficiency which NNES students have, affects their academic performance. The problem under investigation in this case study was the relationship between students’ academic performance in particular modules and how their written responses in examinations contributed to them failing a module. The purpose was to establish to which extent limited English proficiency contributed to the poor academic performance of NNES preservice teachers studying through distance education. This study is underpinned by Cummins’ theory of Basic Interpersonal Communication Skills and Cognitive Academic Language Proficiency (1984). It is supported by related literature which emphasises the challenges NNES students experience in understanding academic content and responding to written assessment tasks in a language other than their home language. A quantitative approach was used which focused on the written responses to examination papers of thirty undergraduate B Ed students who had failed a particular module, at a private higher education institution. The contribution of inadequate or incoherent English, as the reason why marks were not allocated to answers, was calculated and analysed. Results indicated that students’ English grammatical proficiency does have an influence on their academic performance, though it is not the main contributing factor to students failing their modules. For this case study it was determined that the pre-service teachers’ inadequate English written proficiency contributed almost a third (25,6%) of the reasons for their poor academic performance. This finding suggests the need to develop new teaching strategies to accommodate and offer language support to NNES students in higher education institutions that offer qualifications using English as the medium of instruction. / Dissertation (MEd)--University of Pretoria, 2017. / Humanities Education / MEd / Unrestricted