Rajasthanl, Western Hindi, Eastern Hindi, and BiharI

Hindi. It is most important to understand clearly 
what we mean by Hindi, as the word is often used 
ambiguously. It is often, for instance, applied in a 
loose sense to the vernacular speech of the whole of 
Nor th India between the Punjab and Sindh on the 

West, and Bengal on the East. But the philological 
researches of scholars, such as Sir George Grierson, 
have shown that there are really four chief languages 
in this area, namely, Rajasthanl, Western Hindi, 
Eastern Hindi, and Biharl, each having a different 
parentage. Biharl really belongs to a group of lan- 
guages of which Bengali is another member. West- 
ern Hindi is closely connected in origin with Panjabi. 
The word Hindi is also often used to denote modern 
literary High Hindi in contradistinction to Urdu ; but 
both High Hindi and Urdu were, as will be shown below, 
developed from a dialect of Western Hindi. Hindustani 
(or Hindostani) is also a name used sometimes to denote 
the vernaculars of all Hindustan, that is the country 
between the Punjab and Sindh and Bengal, but is also 
sometimes used to mean the simpler speech which is 
the li7igua franca of modern India, and of which both 
Urdu and High Hindi are literary developments.

Special status for Hindi-Sanskrit under Article 351

Special status for Hindi-Sanskrit under Article 351

In 2005,Sanskrit,which already had special status in Article 351 of the Constitution of India as the primary source language for the development of the official standard of Hindi, was also declared to be a classical language.
this was followed by similar declarations for Kannada and Telugu and Malayalam , based on the recommendation of a committee of linguistic experts constituted by the Ministry of Culture, Government of India.
In a 2006 press release, Minister of Tourism & Culture Ambika Soni told the Rajya Sabha the following criteria were laid down to determine the eligibility of languages to be considered for classification as a "Classical Language".
“ High antiquity of its early texts/recorded history over a period of 1500-2000 years; A body of ancient literature/texts, which is considered a valuable heritage by generations of speakers; The literary tradition be original and not borrowed from another speech community; The classical language and literature being distinct from modern, there may also be a discontinuity between the classical language and its later forms or its offshoots.

Austro-asiatic roots of Hindi

Austro-asiatic roots of Hindi
Hindi one of the Indo-Aryan languages a subbranch of Indo-European spoken by 74% of Indians and the Dravidian languages spoken by 23% of Indians.Other languages spoken in India belong to the Austroasiatic,  and a few minor language families and isolates.

The north Indian languages from the Indo-Iranian branch of the Indo-European family evolved from Old Indo-Aryan by way of the Middle Indo-Aryan Prakrit languages and Apabhramsa of the Middle Ages. There is no consensus for a specific time where the modern north Indian languages such as Hindustani, Assamese, Bengali, Gujarati, Marathi,Punjabi, Rajasthani, Sindhi and Oriya emerged, but AD 1000 is commonly accepted.Each language had different influences.