Punjab
The major language spoken in the Punjab is Punjabi. In the Indian Punjab this is written in the Gurmukhi script. Pakistan uses the Shahmukhi script, that is closer to Urdu script. Hindi, written in the Devanagri script, is used widely in the Indian states of Himanchal Pradesh and Haryana. Several dialects of Punjabi are spoken in the different regions. The Majhi dialect is considered to be textbook Punjabi and is shared by both countries.
History of East Pakistan
One of the most divisive issues confronting Pakistan in its infancy was the question of what the official language of the new state was to be. Mohammad Ali Jinnah yielded to the demands of refugees from the Indian states of Bihar and Uttar Pradesh, who insisted that Urdu be Pakistan's official language. Speakers of the languages of West Pakistan (Punjabi, Sindhi, Pushtu, and Baluchi) were upset that their languages were given second-class status. In East Pakistan, the dissatisfaction quickly turned to violence. The Bengalis of East Pakistan constituted a majority (an estimated 54%) of Pakistan's entire population. Their language, Bengali, like Urdu, belongs to the Indo-Aryan language family, but the two languages have different scripts and literary traditions.