Dissertation (MA Linguistics)In the recent years, there has been system of the introduction of education policy changes especially in primary schools among the third world countries including Africa. One among the most areas by which these changes focus is the question of language of instruction whereby local African languages are many times replaced with colonial languages particularly English from upper primary level. In 2006, Zanzibar passed a new education policy. Among many things, the policy changed the language of instruction following the replacement of Kiswahili to English in teaching Science, Mathematics, Information and Communication Technology (ICT), and Geography subjects from two final years of primary education. The main concern of this study was to explore the real situation of teaching and learning through English in Zanzibar public primary schools whereby Science, Mathematics and ICT subjects were proposed subjects. Specifically, the study was confined in examining pupils‟ ability to comprehend lessons in English, teachers‟ ability to teach through English and the quality of the materials used for teaching and learning. The study employed a mixed research approach while purposive sampling technique was used to get the sample of the study. Drawing on the Social Interactionist Theory of language learning, data were collected from the Central and Southern District of the South Region – Unguja through questionnaire, interviews, classroom observations and documentary review. The analysis of the data generated revealed that pupils in primary schools face a tower of challenges from learning through English and, consequently, they do not comprehend lessons well. As well, teachers demonstrated insufficient ability to teach through English. Moreover, the materials used for teaching and learning, specifically textbooks, have several language issues that do not only weaken pupils‟ acquisition of English but sometimes give them a degenerate language input. The study ends up with several recommendations but rewriting of the books used and training of the teachers are of the upfront requirements.