In this paper I argue that language policies for education have effects on pupils’ educational possibilities. With the case of Karagwe district inTanzania, the paper suggests that the policy of ‘Swahili only’ in primary school education inTanzaniafavors the small minority of the school children that live in a context where Swahili is used. This appears to lead to inequality in pupils’ chances in education and to a low level of achievement of academic content in schools. This also promotes the development and use of what I call safety strategies among teachers and pupils that hide failure and prevent pupils’ learning.