Vedic Sanskrit is the name given by modern scholarship to the oldest, attested form of the Proto-Indo-Aryan language. This is the language that was used in the religious hymns known as the Vedas, in particular, the Ṛg-Veda, the oldest of them, dated to have been composed roughly over the period from 1500 to 1000 BCE. It was a purely spoken language during that period used before the introduction of writing in the language. Its grammar differs in certain respects from the grammar of the later Classical Sanskrit.