Under Belgian rule, the colonizers instituted teaching and use of the four national languages in primary schools, making it one of the few African nations to have had literacy in local languages during the European colonial period. This trend was reversed after independence, when French became the sole language of education at all levels. Since 1975, the four national languages have been reintroduced in the first two years of primary education, with French becoming the sole language of education from the third year onward, but in practice many primary schools in urban areas solely use French from the first year of school onward.