Unlocking learner success through mother-tongue instruction and investment in African languages

Ros Clayton

As we celebrate International Mother Language Day on 21 February, we are reminded that South Africa’s linguistic diversity is one of our greatest cultural assets. Yet for decades, African languages were deliberately marginalised in formal education. Even today, economic pressures and the global dominance of English lead many parents to believe that the earlier children are taught in English, the better their academic prospects will be. It is an understandable assumption. But it is not supported by the evidence.

A substantial body of international research shows that children learn to read most effectively when they are first taught in a language they understand deeply. Literacy skills developed in a child’s home language transfer to a second language. In other words, a strong foundation in African languages does not delay English acquisition – it strengthens it. This matters enormously in South Africa, where most learners transition to English as the Language of Learning and Teaching in Grade 4. If English will ultimately be the medium ofinstruction in matric, it may seem intuitive to introduce it from Grade 1.

Yet research consistently demonstrates that children acquire literacy in both their first and second language most effectively when early instruction is delivered in their mother tongue, with structured exposure to English alongside it. Ideally, evidence shows that this home language foundation should be sustained until at least the end of primary school.There is strong evidence from South African that reinforces this conclusion. By exploiting the phased introduction of mother-tongue instruction policies, researchers have previously been able to estimate the causal effect of learning in one’s mother tongue, compared with learning in English.

The findings are striking:learners taught in their home language in the Foundation Phase (Grades 1–3) went on to achieve higher English marks in Grades 4, 5 and 6 than peers who were taught in English from the outset. Far from holding learners back, mother-tongue instruction appears to enhance later English performance. Building on this body of work, my own research at Stellenbosch University – funded by the Optima Trust – extends the existing South African evidence by drawing on far more comprehensive administrative data.

This study examines the relationship between Foundation Phase home language mastery and outcomes at the point of transition to English in Grade 4 using population-level data from six provinces (Eastern Cape, Gauteng, KwaZulu-Natal, Limpopo, Mpumalanga and North West) between 2017 and 2023. This broader dataset – called the Data Driven Districts dataset – allows for a more representative assessment of how home language mastery shapes learner outcomes amongst African mother-tongue learners across diverse provincial contexts.The patterns are clear and consistent. Across all six provinces, stronger Grade 3 home language mastery is closely associated with higher Grade 4 English performance. Each additional percentage point achieved in Grade 3 Home Language is associated with a 0.4 percentage point increase in Grade 4 English marks, underscoring the strength of the link between a solid home language foundation and subsequent success in English.

Learners with better home language foundations are also less likely to repeat Grade 4. These findings suggest that success in English is not achieved by abandoning the home language, but by building on it. The data also reveal important provincial differences in access to mother-tongue instruction. In the Eastern Cape, KwaZulu-Natal, Limpopo, Mpumalanga and North West, more than 80% of African-language learners receive instruction in their home language during the Foundation Phase, and this proportion has remained relatively stable over time.

Gauteng tells a different story. In 2017, 56% of African-language learners were taught in their mother tongue in the Foundation Phase – already lower than in other provinces and likely reflecting the province’s linguistic diversity. By 2023, this figure had dropped to 49%, driven largely by an increase in English-medium instruction. This decline has occurred despite strong policy support for mother-tongue education in the early grades. Understanding why this shift is happening, and how schools can be supported to offer mother-tongue instruction where appropriate, should be a priority. The policy implications are clear. Expanding access to mother-tongue instruction in the Foundation Phase is aligned with the best available evidence. A strong home language foundation supports learners academically and eases the transition to English in Grade 4.

At the same time, improving access to mother-tongue instruction is not enough. Despite high levels of mother-tongue instruction in most provinces, 81% of Grade 4 learners still cannot read for meaning in any language. The challenge is therefore not only whether children are taught in their home language, but how well they are taught. Improving early literacy outcomes will require sustained investment in teacher preparation, high-quality learning materials in African languages, and systematic monitoring of reading progress. If we are serious about improving educational outcomes at scale, we must treat African languages not as obstacles to overcome, but as intellectual resources to cultivate. The evidence is compelling: when children learn first in the language they know best, they are better equipped to succeed in the language they need next.

* Clayton is affiliated with the Research on Socio-Economic Policy (RESEP) group in the Department of Economics at Stellenbosch University.

Weekend Argus