How has Persian influenced the vocabularies of other Iranian languages?

As the national language of Iran and a long-standing literary tradition, Persian has served as a primary donor language for other Iranian languages, significantly shaping their vocabularies over many centuries.12

This influence is widespread, particularly within Iranian territory, where Persian has acted as a dominant cultural and administrative force. Key aspects of this linguistic impact include:1

• General Lexical Borrowing: All other Iranian languages have drawn upon the Persian vocabulary to varying degrees. Even languages that maintain strong distinct identities, such as Kurdish and Balochi, have been and continue to be strongly influenced by Persian. Specifically, Western Balochi has been noted for its direct influence from Persian.213
• Assimilation in Pashto: The Pashto language has incorporated numerous Persian verbs and has assimilated many Arabic words that arrived via their Persianized forms. Additionally, Pashto has borrowed specific terms from Tajik—a variety of Persian—such as ruai-jirge (a common platform) and ilghar (attack).4
• Literary and Cultural Transmission: Because Persian has been a major literary language since the 9th century, it has provided a vocabulary base for the literary and formal expression of neighboring languages.1

While Persian has influenced these languages, it is important to note that Persian itself has undergone significant lexical changes, including the adoption of a large proportion of Arabic loanwords following the Islamic conquest of Iran.125