ACCORDING to the United Nations Education, Scientific and Cultural Organisation languages are "the most powerful instruments of preserving and developing our tangible and intangible heritage".

Sadly, 4percent of the world's spoken languages have become extinct since 1950 and "90percent to 95percent of today's approximately 7000 spoken languages might be extinct or no longer learnt by children by 2100".

Of the world's extinct languages, seven used to be spoken in South Africa, namely !Gan!ne, Cape Khoekhoe, |'Auni, |Xam, ||Ku||'e, ||Kx'au and ||Xeqwi. Today, we have three critically endangered languages: Korana (six speakers in 2008), N|uu (eight speakers in 2008) and Xiri (87 speakers in 2000).

Most South Africans have never heard of these languages and little or nothing has been done to preserve them.

But the biggest threat to our indigenous languages does not come from the government but from the indifference of the speakers of these languages.

Despite the emphasis that the Constitution places on language rights, the use of mother tongues is under serious threat. English has become the de facto language of the government despite the fact that it's only the sixth largest language in the country (following isiZulu, isiXhosa, Afrikaans, Sepedi and Setswana).

While there are many groups that advocate the language and education rights of Afrikaans speakers, the same is not true of our other indigenous languages - which are becoming increasingly marginalised in all spheres of life.

But why is one's mother language, and especially mother-tongue education, so important?

Dr Neville Alexander says an "English-only or English-mainly policy necessarily condemns most people, and thus the country as a whole to a permanent state of mediocrity, since people are unable to be spontaneous, creative and self-confident if they cannot use their first language".

He says "bilingual education is the best way for children, whose mother language is not English, to gain skills, information and to learn English" and that the "acquiring or obtaining of skills by means of Afrikaans or any other indigenous language is the way to true equality".

Dr Kathleen Heugh, a language expert, has found that for a learner to achieve optimal cognitive and academic development, uninterrupted education in the leaner's mother language is required for as long as possible.

The ideal is six to eight years in well equipped schools, and in badly equipped schools until Grade 9. Professor Michael le Cordeur agrees. According to him, mother-tongue education means that "learners are taught the fundamental concepts of a subject in their mother language. As soon as learners understand these concepts, they can apply them when learning a second language. Children understand these concepts more easily in a language that they are familiar with. In a second language it becomes dead words that are memorised, not internalised."

There can be no doubt about the importance of mother language. And yet many South Africans are not heeding the message. Why? Research points to the existence of myths regarding the use of mother language and mother-tongue education.

Section 29 of the Constitution entitles South Africans to the right to education in a language of their choice, but does not specifically refer to mother-tongue education. Children cannot choose the language of education, while the majority of black parents prefer their children to switch to English as the language of education as soon as possible - with negative consequences for their children's education and for the survival of indigenous languages and cultures.

According to Heugh, one of the myths that many parents have is that "English is the only language that has the capacity to deliver quality education to the majority -African languages cannot".

Alexander says that this blind belief in the superiority of English is a brutal illusion.

So what should be done to rectify these misconceptions? The government needs to launch an action plan that will educate citizens on the importance of mother-tongue education.

African language speakers in particular need to mobilise to promote their languages. Afrikaans cannot remain the only local language that is preserved.

But no language will survive if its speakers do not support it. There is a saying: "If you can speak three languages you're trilingual. If you can speak two languages you're bilingual. If you can speak only one you're an American." We shouldn't allow this to happen to us as South Africans, and to our rich heritage of indigenous languages and cultures.

• The writer is a researcher at the FW de Klerk Foundation