Africans speak African languages in their everyday lives while lessons in school are delivered in an exogenous language. In many places adult education is also carried out in a language the majority of people do not speak. The exogenous languages, which are the languages of the former colonial powers and mastered just by a small African elite, are used in most parliaments in Africa and in most newspapers. This problem is largely ignored by the international community. An argument often put forward against using African languages as Languages of Instruction (LOIs) is that there are so many of them, and it may be problematic to select one as an LOI. But is this really the case? And does one need to select one language? The main work of the Centre for Advanced Studies of African Society (CASAS) located in Cape Town has been to harmonise the written forms of most African languages so that these languages can be used as LOIs and as languages of government and the press. This paper examines in some detail the work undertaken by CASAS, its successes and challenges. It shows that the political process of getting the harmonised languages adopted is more difficult and unpredictable than the linguistic work itself.