New Delhi, April 24 -- The Vice President of India, Shri M. Venkaiah Naidu has called upon to people to take a pledge to preserve and promote their mother tongue. Stressing that there was a need to strengthen the campaign for preserving mother tongue, he urged upon State governments to make mother tongue mandatory up to primary school level. Expressing his keen interest in protecting native languages, the Vice President advised students to speak in their mother tongue at home. Shri Naidu while addressing the gathering at the Platinum Jubilee Celebrations of Kesari Schools, in Chennai today, he advised educational institutions to cultivate the quest for innovation and spirit of scientific thinking in children. He also laid foundation stone f...