Mother tongue being cut out
Failure to teach in indigenous languages is detrimental to future generations.
With the 2011 census showing a decline in six of the 11 official languages, linguists are warning that failure to teach in home languages will lead to continued failures at schools and universities.
With a decline in the use of Zulu, Sepedi, Sotho, Tswana and Swati, the head of the Wits University language school, Nhlanhla Thwala said: "Teaching pupils in their mother tongue is imperative to ensuring success at schools and tertiary institutions."
While most indigenous languages showed a decrease in popularity, English, Afrikaans and Ndebele recorded increases, with 9.6%, 13.5% and 2.1% of the population speaking these languages respectively.
Zulu and Xhosa remained the most popular languages, with 22.7% (11.5million people) and 16% (8million people) of the population speaking them respectively. The number of whites and Indians speaking Zulu increased.
Although decreasing in popularity in the Northern Cape and Western Cape, Afrikaans is the third-most-popular language.
English language speakers increased to 4.9million from 3.7million in 2001.
Thwala said South Africa's "tragedy" was that even though so many indigenous languages were spoken, children were not taught in them.
"We are essentially ignoring well-known facts - if you want to learn you must do so in your mother tongue. If we do not, South Africa will continue to experience high failure rates in schools and universities," he said.
Languages reflected the power dynamics of a country, Thwala said.
"People speak a language for a reason. Increases and decreases show which languages people find useful, regardless of whether they are their first language."
While the increases were not surprising, the changes were, Thwala said.
"The popularity of Zulu and Xhosa are understandable, with Zulu South Africa's de facto second language. People hear Zulu more than other languages, therefore there is a greater expectation to speak it."
Research showed Zulu, the most widely recognised of the Nguni languages, was by far the most requested by people wanting to learn a language, he said.
While the increase in Afrikaans was surprising, once a language gained an advantage - be it through the amount of school materials or available teachers - it was difficult to undermine.
"Social engineering to either promote or undermine languages does not work.
"This is evident from fanakalo, which, while not official continues to be spoken, especially on mines."