How is Persian related to the Indo-European language family?

Persian is a member of the Iranian branch of the Indo-Iranian language family, which is itself a distinct subgroup of the Indo-European language family.123

The relationship is evidenced by shared linguistic features, including grammatical structures and vocabulary. For instance, while Modern Persian has simplified its grammar compared to its ancestors, its verbs retain personal endings that are related to those found in other Indo-European languages. Furthermore, the Iranian and Indo-Aryan branches share significant commonalities in their phonological development from Proto-Indo-European, such as the evolution of specific vowel sounds and consonant clusters.124

Historical evidence also highlights this connection through shared terminology. Speakers of both Iranian and Indo-Aryan languages used similar terms to refer to themselves, such as the Old Persian ariya-, which corresponds to the Sanskrit ārya- (Aryan). These linguistic and historical links confirm that Persian is deeply rooted in the broader Indo-European language family.213