Bialystok (2015) argues that the bilingual’s cognitive benefit is related to the continuous supervision and the need for conflict resolution that happens when dual languages are co-activated. One framework that clearly projects the experience of the bilingual, in terms of swapping languages is the bilingual’s language modes (BLMs) by Grosjean (2001). In this review paper, we have highlighted the policy of medium of instruction for teaching English in primary schools in Ghana. Again, we have briefly described the tenants of the BLMs, and demonstrated how these modes can be applied on the Ghanaian bilingual primary schools. On the basis of the BLMs, we argue that the most suitable medium of instruction for teaching and learning of English as a second language at the primary level (primary 1 - 6) of a diverse Ghanaian multilingual society should be English language, and the mother tongue of the community within which the school is situated. This argument is in conformism with Anyidoho (2009), and Owusu et al. (2015). Consequently, this paper would enable the key stakeholders of Ghanaian primary schools, to reexamine the policy of instruction for teaching English in Ghanaian primary schools, by placing prominence on the first language of the various speech communities in Ghana.