In the sociopolitical realm, Urdu and Hindi are different languages, but the colloquial basis of both is identical, and as a written language Urdu differs from Hindi principally in its greater acceptance of Persian-Arabic vocabulary and in some syntactic features. It is written in the {{link=Arabic alphabet">Arabic alphabet with modification of some letters to denote specifically Indo-Aryan sounds. As Pakistan's official language, Urdu has been promoted as a token of national unity, though less than 8% of Pakistanis
mainly immigrants and descendants of immigrants from India after the 1947 partition
speak it as a first language.