Abstract
Questions have been asked about whether science is more special than any other subject in being less culture bound, and less subject to the usual differences between languages. At so many angles scientific language has been viewed as difficult because of its academic, authoritative and impersonal nature which makes it difficult for both teachers and learners to understand. This is an unfortunate reality because learners ought to develop a strong foundational understanding of scientific concepts in order to comprehend scientific knowledge and processes. Previous studies have shown how language acts as a possible barrier to scientific concept formation. Consequently, the current paper reports on a study to determine how the nature of scientific language impact on the teaching of grade 7 Natural Sciences. Guided by the socio-cultural theory as a framework the study adopted a qualitative case-study research approach. From two different schools in Johannesburg, four Natural Sciences teachers and their grade 7 Natural Sciences learners were purposefully selected to participate in the study. Each teacher was observed twice while teaching Natural Sciences to grade 7 learners and the observations were captured using Reformed Teaching Observation Protocol (RTOP). Each lesson observation was followed by semi-structured interviews to accord the teachers an opportunity to explain some of the episodes observed in the lessons. Data collected was subjected to constant comparative analysis. The results showed that both teachers and learners struggled with writing, pronouncing and spelling scientific terminologies regardless of their proficiency in the language of teaching and learning. The teachers indicated that their learners failed to understand the scientific concepts and processes when they explain to them in English. The lack of fluency in English reduced the participation of learners during the teaching and learning process particularly where teachers had zero tolerance for learners' use of home languages to answer questions. What came out strongly from the lesson observations was that whether learners were first or second English language speakers, the teachers' abilities to scaffold learning was essential to ensure science concepts were comprehensible to the learners. Concepts were more accessible to the learners in classrooms where the teachers utilised different ICT tools which lowered the impact of scientific language. The findings have implications for both pre-service and in-service teacher professional development programmes to equip teachers with the knowledge and skills for making science more comprehensible to the learners.