They speak urdu
http://en.wikipedia.org/wiki/Urdu_langua…
It is similar to Hindi. Urdu is often contrasted with Hindi, another standardised form of Hindustani.[14] The main differences between the two are that Standard Urdu is conventionally written in Nastaliq calligraphy style of the Perso-Arabic script and draws vocabulary more heavily from Persian and Arabic,[15] while Standard Hindi is conventionally written in Devanāgarī and draws vocabulary from Sanskrit comparatively[16] more heavily.[5] Most linguists nonetheless consider Urdu and Hindi to be two standardized forms of the same language;[17][18] others classify them separately [19], while some consider any differences to be sociolinguistic.[20] It should be noted, however, that mutual intelligibility decreases in literary and specialized contexts. Furthermore, due to religious nationalism since the partition of British India and consequent continued communal tensions, native speakers of both Hindi and Urdu increasingly assert them to be completely distinct languages.