Vedic Sanskrit

[3][4] Extensive ancient literature in the Vedic Sanskrit language has survived into the modern era, and this has been a major source of information for reconstructing Proto-Indo-European and Proto-Indo-Iranian history.

[8] Both Asko Parpola (1988) and J. P. Mallory (1998) place the locus of the division of Indo-Aryan from Iranian in the Bronze Age culture of the Bactria–Margiana Archaeological Complex (BMAC).

The language in the early Upanishads of Hinduism and the late Vedic literature approaches Classical Sanskrit.

[13] Five chronologically distinct strata can be identified within the Vedic language:[14][15][16] The first three are commonly grouped together, as the Saṃhitās[A] comprising the four Vedas:[B] ṛg, atharvan, yajus, sāman, which together constitute the oldest texts in Sanskrit and the canonical foundation both of the Vedic religion, and the later religion known as Hinduism.

[19] Many words in the Vedic Sanskrit of the Ṛg·veda have cognates or direct correspondences with the ancient Avestan language, but these do not appear in post-Rigvedic Indian texts.

The pre-1200 BCE layers mark a gradual change in Vedic Sanskrit, but there is disappearance of these archaic correspondences and linguistics in the post-Rigvedic period.

This must have occurred before the time of Pāṇini because Panini makes a list of those from the northwestern region of India who knew these older rules of Vedic Sanskrit.

[15] These texts elucidate the state of the language which formed the basis of Pāṇini's codification into Classical Sanskrit.

[22] The following differences may be observed in the phonology: Vedic had a pitch accent[29] which could even change the meaning of the words, and was still in use in Pāṇini's time, as can be inferred by his use of devices to indicate its position.