In Tanzania there are at least three clusters of languages: Kiswahili which is one of the two official languages, which is a local lingua franca (receiving institutional protection and support), English which is the other official language (also receiving institutional protection and support), and ethnic community languages, amounting to 150 (not receiving institutional protection or support). The language policy on the medium of instruction designates Kiswahili an exclusive role of the medium of instruction throughout public primary schools. However, the fact is, in remote rural areas of Tanzania Kiswahili is rarely used. The literacy situation in primary schools in such locales, particularly in beginner classes, is pathetic as pupils cannot interact with their teachers in the classrooms. As a result there is almost no learning. In turn, generalised policies, only serve the role of gate-keeping. The current work presents lessons from two linguistically different contexts in Tanzania, showing how the medium of instruction can have significant impact on an educational system.