Vic publicado hace 4 mes(es) How much of India speaks Hindi? Is it the "common" language of India, in the way that Mandarin is for Chinese?
Vic, Hindi is the National Language just as Susmita said.
Majority of the Indians use this language, English and Hindi are two common languages used here. Though there are other regional languages too but even the people who speak in a regional language know either one or both of the languages(Hindi and English).