The grammar of the Sanskrit language has a complex verbal system, rich nominal declension, and extensive use of compound nouns. It was studied and codified by Sanskrit grammarians from the later Vedic period (roughly 8th century BCE), culminating in the Pāṇinian grammar of the 6th century BCE.
Sanskrit grammatical tradition (vyākaraṇa, one of the six Vedanga disciplines) began in late Vedic India and culminated in the Aṣṭādhyāyī of Pāṇini, which consists of 3990 sutras (ca. 5th century BCE). About a century after Pāṇini (around 400 BCE), Kātyāyana composed vārtikas (explanations) on the Pāṇinian sũtras. Patañjali, who lived three centuries after Pāṇini, wrote the Mahābhāṣya, the "Great Commentary" on the Aṣṭādhyāyī and Vārtikas. Because of these three ancient Sanskrit grammarians this grammar is called Trimuni Vyākarana. Jayaditya and Vāmana wrote a commentary named Kāśikā in 600 CE. Kaiyaṭa's (12th century AD) commentary on Patañjali's Mahābhāṣya also exerted much influence on the development of grammar, but more influential was the Rupāvatāra of Buddhist scholar Dharmakīrti which popularised simplified versions of Sanskrit grammar.