In South Africa, linguistic diversity is high that policy makers and teachers are being faced with complex issues regarding
appropriate ways of teaching a multilingual school population. Majority of teachers and learners come from a language
background other than English, yet the language of teaching and learning in most schools is English. This paper reports on a
research project which sought to explore the conceptions of English additional language (EAL) teachers about their teaching of
Physical science in the medium of English. In this case study the data were collected from semi-structured interviews and
lesson observations of four experienced EAL teachers in the KwaZulu-Natal Province of South Africa. Analysis of results
showed that a majority of teachers prefer to code-switch, using of both English as well as mother tongue in their classrooms.
Whilst there are many factors that influence this code-switching, teachers might use this to ease the problems of understanding
on the side of the learners. On the other, teachers challenged by the complexities of second language teaching might prefer to
use the children’s mother tongue. Other dynamics include teachers who do not possess the required social and cultural capital
linked to the second language. The conclusions found that apprehensive with the thought of examinations they tend to teach in
a language they think their learners would understand better. These findings are significant because they contributes to a
dynamic notion of additive bilingualism and that more work is required in teachers’ pre-service and in-service training so as to
enable them promote multilingualism as enshrined in the South African constitution.