The Indo-Aryan or Indic languages are a major language family of South Asia (or the Indian subcontinent). They constitute a branch of the Indo-Iranian languages, itself a branch of the Indo-European language family. In the early 21st century, Indo-Aryan languages were spoken by more than 800 million people, primarily in India, Bangladesh, Nepal, Pakistan and Sri Lanka. Moreover, there are large immigrant and expatriate Indo-Aryan speaking communities in Northwestern Europe, Western Asia, North America and Australia. There are about 219 known Indo-Aryan languages in the world.
Modern Indo-Aryan languages are descended from Sanskrit through Prakrit. The largest in terms of speakers are Hindustani (Hindi-Urdu, about 329 million), Bengali (242 million), Punjabi (about 120 million) , Marathi, (112 million), Gujarati (60 million), Bhojpuri (51 million), Odia (34 million), Maithili (about 34 million), Sindhi (25 million) and other languages, with a 2005 estimate placing the total number of native speakers at nearly 900 million.
Proto-Indo-Aryan, or sometimes Proto-Indic, is the reconstructed proto-language of the Indo-Aryan languages. It is intended to reconstruct the language of the pre-Vedic Indo-Aryans. Proto-Indo-Aryan is meant to be the predecessor of Old Indo-Aryan (1500–300 BCE) which is directly attested as Vedic and Mitanni-Aryan. Despite the great archaicity of Vedic, however, the other Indo-Aryan languages preserve a small number of archaic features lost in Vedic.
From the Rigvedic language, "Sanskrit" (literally "put together", meaning perfected or elaborated) developed as the prestige language of culture, science and religion, as well as the court, theatre, etc. Sanskrit is, by convention, referred to by modern scholars as 'Classical Sanskrit' in contradistinction to the so-called 'Rigvedic Sanskrit', which is largely intelligible to Sanskrit speakers.
Mitanni inscriptions show some middle Indo-Aryan characteristics along with Old Indo-Aryan, for example sapta in old Indo-Aryan becomes satta ('pt' is transformed into middle indo aryan 'tt'). According to S.S. Misra this language can be similar to Buddhist hybrid Sanskrit which might not be a mixed language but an early middle Indo-Aryan occurring much before prakrit.[n 1][n 2]
Outside the learned sphere of Sanskrit, vernacular dialects (Prakrits) continued to evolve. The oldest attested Prakrits are the Buddhist and Jain canonical languages Pali and Ardhamagadhi Prakrit, respectively. By medieval times, the Prakrits had diversified into various Middle Indo-Aryan languages. Apabhraṃśa is the conventional cover term for transitional dialects connecting late Middle Indo-Aryan with early Modern Indo-Aryan, spanning roughly the 6th to 13th centuries. Some of these dialects showed considerable literary production; the Śravakacāra of Devasena (dated to the 930s) is now considered to be the first Hindi book.
The next major milestone occurred with the Muslim conquests in the Indian subcontinent in the 13th–16th centuries. Under the flourishing Turco-Mongol Mughal Empire, Persian became very influential as the language of prestige of the Islamic courts due to adoptation of the foreign language by the Mughal emperors. However, Persian was soon displaced by Hindustani. This Indo-Aryan language is a combination with Persian, Arabic, and Turkic elements in its vocabulary, with the grammar of the local dialects.
The Indo-Aryan languages of North India and Pakistan form a dialect continuum. What is called "Hindi" in India is frequently Standard Hindi, the Sanskritized version of the colloquial Hindustani spoken in the Delhi area since the Mughals. However, the term Hindi is also used for most of the central Indic language varieties from Bihar to Rajasthan. The spoken New Indo-Aryan dialects from Assam in the east to the borders of Afghanistan in the west form a linguistic continuum across the plains of North India, Pakistan and Bangladesh.
In the Central Zone Hindi-speaking areas, for a long time the prestige dialect was Braj Bhasha, but this was replaced in the 19th century by the Khariboli-based Hindustani. Hindustani was strongly influenced by Sanskrit and Persian, with these influences leading to the emergence of Modern Standard Hindi and Modern Standard Urdu as registers of the Hindustani language. This state of affairs continued until the division of the British Indian Empire in 1947, when Hindi became the official language in India and Urdu became official in Pakistan. Despite the different script the fundamental grammar remains identical, the difference is more sociolinguistic than purely linguistic. Today it is widely understood/spoken as a second or third language throughout South Asia and one of the most widely known languages in the world in terms of number of speakers.
Some theonyms, proper names and other terminology of the Mitanni exhibit an Indo-Aryan superstrate, suggest that an Indo-Aryan elite imposed itself over the Hurrians in the course of the Indo-Aryan expansion. In a treaty between the Hittites and the Mitanni, the deities Mitra, Varuna, Indra, and the Ashvins (Nasatya) are invoked. Kikkuli's horse training text includes technical terms such as aika (eka, one), tera (tri, three), panza (pancha, five), satta (sapta, seven), na (nava, nine), vartana (vartana, turn, round in the horse race). The numeral aika "one" is of particular importance because it places the superstrate in the vicinity of Indo-Aryan proper as opposed to Indo-Iranian or early Iranian (which has "aiva") in general
Another text has babru (babhru, brown), parita (palita, grey), and pinkara (pingala, red). Their chief festival was the celebration of the solstice (vishuva) which was common in most cultures in the ancient world. The Mitanni warriors were called marya, the term for warrior in Sanskrit as well; note mišta-nnu (= miẓḍha, ≈ Sanskrit mīḍha) "payment (for catching a fugitive)" (M. Mayrhofer, Etymologisches Wörterbuch des Altindoarischen, Heidelberg, 1986–2000; Vol. II:358).
Sanskritic interpretations of Mitanni royal names render Artashumara (artaššumara) as Ṛtasmara "who thinks of Ṛta" (Mayrhofer II 780), Biridashva (biridašṷa, biriiašṷa) as Prītāśva "Whose Horse is Dear" (Mayrhofer II 182), Priyamazda (priiamazda) as Priyamedha "whose wisdom is dear" (Mayrhofer II 189, II378), Citrarata as Citraratha "Whose Chariot is Shining" (Mayrhofer I 553), Indaruda/Endaruta as Indrota "helped by Indra" (Mayrhofer I 134), Shativaza (šattiṷaza) as Sātivāja "Winning the Race Price" (Mayrhofer II 540, 696), Šubandhu as Subandhu "Having Good Relatives" (a name in Palestine, Mayrhofer II 209, 735), Tushratta (tṷišeratta, tušratta, etc.) as *tṷaiašaratha, Vedic Tvastar "Whose Chariot is Vehement" (Mayrhofer, Etym. Wb., I 686, I 736).
Domari is an Indo-Aryan language spoken by older Dom people scattered across the Middle East. The language is reported to be spoken as far north as Azerbaijan and as far south as central Sudan.:1 Based on the systematicity of sound changes, we know with a fair degree of certainty that the names Domari and Romani derive from the Indo-Aryan word ḍom.
The Romani language is usually included in the Western Indo-Aryan languages. Romani—spoken mainly in various parts of Europe—is conservative in maintaining almost intact the Middle Indo-Aryan present-tense person concord markers, and in maintaining consonantal endings for nominal case—both features that have been eroded in most other modern languages of Central India. It shares an innovative pattern of past-tense person concord with the languages of the Northwest, such as Kashmiri and Shina. This is believed to be further proof that Romani originated in the Central region, then migrated to the Northwest.
There are no known historical documents about the early phases of the Romani language.
Linguistic evaluation carried out in the nineteenth century by Pott (1845) and Miklosich (1882–1888) showed that the Romani language is to be classed as a New Indo-Aryan language (NIA), not Middle Indo-Aryan (MIA), establishing that the ancestors of the Romani could not have left India significantly earlier than AD 1000.
The principal argument favouring a migration during or after the transition period to NIA is the loss of the old system of nominal case, and its reduction to just a two-way case system, nominative vs. oblique. A secondary argument concerns the system of gender differentiation. Romani has only two genders (masculine and feminine). Middle Indo-Aryan languages (named MIA) generally had three genders (masculine, feminine and neuter), and some modern Indo-Aryan languages retain this old system even today.
It is argued that loss of the neuter gender did not occur until the transition to NIA. Most of the neuter nouns became masculine while a few feminine, like the neuter अग्नि (agni) in the Prakrit became the feminine आग (āg) in Hindi and jag in Romani. The parallels in grammatical gender evolution between Romani and other NIA languages have been cited as evidence that the forerunner of Romani remained on the Indian subcontinent until a later period, perhaps even as late as the tenth century.
There can be no definitive enumeration of Indo-Aryan languages because their dialects merge into one another. The major ones are illustrated here; for the details, see the dedicated articles.
Ethnologue lists the following languages under the Western Zone that are not already covered in other subgroups:
Parya historically belonged to the Central Zone but lost intelligibility with other languages of the group due to geographic distance and numerous grammatical and lexical innovations.
This group of languages developed from Maharashtri Prakrit. It is not clear if Dakhini (Deccani, Southern Urdu) is part of Hindustani along with Standard Urdu, or a separate Persian-influenced development from Marathi.
The Insular Indo-Aryan languages share several characteristics that set them apart significantly from the continental languages.
The following languages are related to each other, but otherwise unclassified within Indo-Aryan:
The following other poorly attested languages are listed as unclassified within the Indo-Aryan family by Ethnologue 17:
Also Degaru, Mina, Bhalay and Gowlan are all names for the Gowli caste, rather than a language.
The normative system of New Indo-Aryan stops consists of five points of articulation: labial, dental, "retroflex", palatal, and velar, which is the same as that of Sanskrit. The "retroflex" position may involve retroflexion, or curling the tongue to make the contact with the underside of the tip, or merely retraction. The point of contact may be alveolar or postalveolar, and the distinctive quality may arise more from the shaping than from the position of the tongue. Palatals stops have affricated release and are traditionally included as involving a distinctive tongue position (blade in contact with hard palate). Widely transcribed as [tʃ], Masica (1991:94) claims [cʃ] to be a more accurate rendering.
Moving away from the normative system, some languages and dialects have alveolar affricates [ts] instead of palatal, though some among them retain [tʃ] in certain positions: before front vowels (esp. /i/), before /j/, or when geminated. Alveolar as an additional point of articulation occurs in Marathi and Konkani where dialect mixture and others factors upset the aforementioned complementation to produce minimal environments, in some West Pahari dialects through internal developments (*t̪ɾ, t̪ > /tʃ/), and in Kashmiri. The addition of a retroflex affricate to this in some Dardic languages maxes out the number of stop positions at seven (barring borrowed /q/), while a reduction to the inventory involves *ts > /s/, which has happened in Assamese, Chittagonian, Sinhala (though there have been other sources of a secondary /ts/), and Southern Mewari.
Further reductions in the number of stop articulations are in Assamese and Romany, which have lost the characteristic dental/retroflex contrast, and in Chittagonian, which may lose its labial and velar articulations through spirantisation in many positions (> [f, x]). 
Sanskrit was noted as having five nasal-stop articulations corresponding to its oral stops, and among modern languages and dialects Dogri, Kacchi, Kalasha, Rudhari, Shina, Saurasthtri, and Sindhi have been analysed as having this full complement of phonemic nasals /m/ /n/ /ɳ/ /ɲ/ /ŋ/, with the last two generally as the result of the loss of the stop from a homorganic nasal + stop cluster ([ɲj] > [ɲ] and [ŋɡ] > [ŋ]), though there are other sources as well.
The following are consonant systems of major and representative New Indo-Aryan languages, as presented in Masica (1991:106–107), though here they are in IPA. Parentheses indicate those consonants found only in loanwords: square brackets indicate those with "very low functional load". The arrangement is roughly geographical.
In the context of South Asia, the choice between the appellations "language" and "dialect" is a difficult one, and any distinction made using these terms is obscured by their ambiguity. In one general colloquial sense, a language is a "developed" dialect: one that is standardised, has a written tradition and enjoys social prestige. As there are degrees of development, the boundary between a language and a dialect thus defined is not clear-cut, and there is a large middle ground where assignment is contestable. There is a second meaning of these terms, in which the distinction is drawn on the basis of linguistic similarity. Though seemingly a "proper" linguistics sense of the terms, it is still problematic: methods that have been proposed for quantifying difference (for example, based on mutual intelligibility) have not been seriously applied in practice; and any relationship established in this framework is relative.