اُردو لفظ Urdu ( Urdu: اُردُو, or more precisely Modern Standard Urdu, is a standardized register of the Hindustani language. Urdu is historically associated with the Muslims of the region of Hindustan. It is the national language and lingua franca of Pakistan, and an official language of six Indian states and one of the 22 scheduled languages in the Constitution of India. Apart from specialized vocabulary, Urdu is mutually intelligible with Standard Hindi, which is associated with the Hindu community. Since the end of the Mughal period in the nineteenth century, varieties of Hindustani have been the lingua franca for much of South Asia. Urdu and Hindi are nearly identical in basic structure and grammar, and at a colloquial level also in vocabulary and phonology. If considered the same language, the population of Hindi-Urdu speakers is the fourth largest of the languages of the world, after Mandarin Chinese, English and Spanish. The word Urdu is derived from the same Turkic word ordu (army) that has given English horde. From the establishment of the Delhi Sultanate and the Mughal Empire until the British Raj, Hindustani, written in the Urdu script, was the language of both Hindus and Muslims. The language was variously known as Hindi, Hindavi and Dehlavi. The communal nature of the language lasted until it replaced Persian as the official language in 1837 and was made co-official, along with English. This triggered a Hindu backlash in northwestern India, which argued that the language should be written in the native Devanagari script. Thus a new literary register, called Hindi, replaced traditional Hindustani as the official language of Bihar in 1881, establishing a sectarian divide of Urdu for Muslims and Hindi for Hindus, a divide that was formalized with the division of India and Pakistan after independence (though there are Hindu poets who continue to write in Urdu to this day). At independence, Pakistan established a highly Persianized literary standard of Urdu as its national language. Although there have been attempts to purify Urdu and Hindi by purging them of, respectively, their Sanskrit and Persian loan words, and new vocabulary draws primarily from Persian and Arabic for Urdu and from Sanskrit for Hindi, this has primarily affected academic and literary vocabulary, and both national standards remain heavily influenced by both Persian and Sanskrit. English has exerted a heavy influence on both as a co-official language. There are between 60 and 70 million native speakers of Urdu: there were 52 million in India per the 2001 census, some 6% of the population; 13 million in Pakistan in 2008, or 8%; and several hundred thousand in the United Kingdom, Saudi Arabia, United States, and Bangladesh, where it is called Bihari. However, a knowledge of Urdu allows one to speak with far more people than that, as Hindi-Urdu is the fourth most commonly spoken language in the world, after Mandarin, English, and Spanish. Because of the difficulty in distinguishing between Urdu and Hindi speakers in India and Pakistan, as well as estimating the number of people for whom Urdu is a second language, the estimated number of speakers is uncertain and controversial. Owing to interaction with other languages, Urdu has become localized wherever it is spoken, including in Pakistan itself. Urdu in Pakistan has undergone changes and has lately incorporated and borrowed many words from Pakistani languages like Pashto, Punjabi, Sindhi and Balti as well as former East Pakistan (now Bangladesh) Bengali language, thus allowing speakers of the language in Pakistan to distinguish themselves more easily and giving the language a decidedly Pakistani flavour. Similarly, the Urdu spoken in India can also be distinguished into many dialects like Dakhni (Deccan) of South India, and Khariboli of the Punjab region since recent times. Because of Urdu''s similarity to Hindi, speakers of the two languages can easily understand one another if both sides refrain from using specialized vocabulary. The syntax (grammar), morphology, and the core vocabulary are essentially identical. Thus linguists usually count them as one single language and contend that they are considered as two different languages for socio-political reasons. In Pakistan Urdu is mostly learned as a second or a third language as nearly 93% of Pakistan''s population has a mother tongue other than Urdu. Despite this, Urdu was chosen as a token of unity and as a lingua franca so as not to give any native Pakistani language preference over the other. Urdu is therefore spoken and understood by the vast majority in some form or another, including a majority of urban dwellers in such cities as Karachi, Lahore, Sialkot, Rawalpindi, Islamabad, Multan, Faisalabad, Hyderabad, Peshawar, Quetta, Jhang, Sargodha and Skardu. It is written, spoken and used in all provinces/territories of Pakistan despite the fact that the people from differing provinces may have different indigenous languages, as from the fact that it is the base language of the country. For this reason, it is also taught as a compulsory subject up to higher secondary school in both English and Urdu medium school systems. This has produced millions of Urdu speakers from people whose mother tongue is one of the State languages of Pakistan such as Punjabi, Pashto, Sindhi, Balochi, Potwari, Hindko, Pahari, Saraiki, Balti, and Brahui who can read and write only Urdu. It is absorbing many words from the regional languages of Pakistan. This variation of Urdu is sometimes referred to as Pakistani Urdu.