Proto-Iranian is the reconstructed ancestor of the Iranian languages, which are a branch of the Indo-Iranian languages. It is believed to have been spoken around 1000 BCE to 500 BCE in the region that is now Iran and parts of Central Asia. Linguists have pieced together its features through the study of later languages, such as Persian and Avestan. The development of Proto-Iranian marked a significant linguistic evolution, leading to the diversification of languages within the Iranian group. This period saw the emergence of distinct dialects, which eventually evolved into the various modern languages we recognize today, including Kurdish, Pashto, and Farsi.