Vedic Sanskrit
The phonetic differences between Vedic Sanskrit and Classical Sanskrit, as discerned from the current state of the surviving literature, are negligible when compared to the intense change that must have occurred in the pre-Vedic period between Indo-Aryan language and the Vedic Sanskrit. The noticeable differences between the Vedic and the Classical Sanskrit include the much-expanded grammar and grammatical categories as well as the differences in the accent, the semantics and the syntax. There are also some differences between how some of the nouns and verbs end, as well as the "sandhi" rules, both internal and external. Quite many words found in the early Vedic Sanskrit language are never found in late Vedic Sanskrit or Classical Sanskrit literature, while some words have different and new meanings in Classical Sanskrit when contextually compared to the early Vedic Sanskrit literature.