Bilingualism is one of the by-products of globalization and migration. As people from different ethnicities come into contact, their languages will influence each other. People learn a second or third language in different environments leading to their linguistic proficiency levels being different. In conversations involving bilinguals, code-switching may be prevalent. This practise of alternating between two or more languages during a speech act has been of great interest to researchers with various models and hypotheses being proposed to explain it. Although code-switching has been studied extensively in literature, indigenous languages such as Shona have received less attention. This study aims to determine whether the markedness model of code-switching can be applied to Shona oral discourse (speech). An analysis is done to ascertain the nature, occurrence and characteristics of code-switching in the speech of Shona-English bilinguals. Participants who attended formal education for at least ten years were selected for the study. In order to inform on the theoretical background and on previous studies that dealt with code-switching, a literature review was conducted. The study used semi-structured interviews, a cloze test and recordings as data collection methods. Data was analysed to determine the applicability of the markedness model to the compiled corpus. Data analysis was also aided by WordSmith, (corpus analysis software). Results of the analysis seem to suggest that the markedness model can be applied to Shona-English code-switching. In addition, an analysis of the corpus using WordSmith showed frequently used English words and collocations and concordances of the code-switched words. An examination of the collocations and concordances shows the contexts in which the code-switched words appear.