Persian language

Persian (/ˈpɜːrʒən/ or /ˈpɜːrʃən/), also known by its endonym Farsi (English: /ˈfɑːrsiː/; Persian: فارسی fārsi [fɒːɾˈsiː]), is the predominant modern descendant of Old Persian, a southwestern Iranian language within the Indo-Iranian branch of the Indo-European languages. It is primarily spoken in Iran, Afghanistan (officially known as Dari since 1958 for political reasons), and Tajikistan (officially known as Tajiki since the Soviet era for political reasons), and some other regions which historically came under Persian influence. The Persian language is classified as a continuation of Middle Persian, the official religious and literary language of Sassanid Persia, itself a continuation of Old Persian, the language of the Achaemenid Persian Empire. Persian is a pluricentric language and its grammar is similar to that of many contemporary European languages. Persian is so-called due to its origin from the capital of the Achaemenid empire, Persis (Fars or Pars), hence the name Persian (Farsi or Parsi). A Persian-speaking person may be referred to as Persophone.

Dari language

Dari (Persian: دری‎‎ [dæˈɾiː]) or Dari Persian (Persian: فارسی دری‎‎ [fɒːɾsije dæˈɾiː]) is the variety of the Persian language spoken in Afghanistan. Dari is the term officially recognized and promoted since 1964 by the Afghan government for the Persian language. Hence, it is also known as Afghan Persian in many Western sources.

As defined in the Constitution of Afghanistan, it is one of the two official languages of Afghanistan; the other is Pashto. Dari is the most widely spoken language in Afghanistan and the native language of approximately 25–50% of the population, serving as the country's lingua franca. The Iranian and Afghan types of Persian are mutually intelligible, with differences found primarily in the vocabulary and phonology.

By way of Early New Persian, Dari Persian, like Iranian Persian and Tajik, is a continuation of Middle Persian, the official religious and literary language of the Sassanian Empire (224–651 CE), itself a continuation of Old Persian, the language of the Achaemenids (550–330 BC). In historical usage, Dari refers to the Middle Persian court language of the Sassanids.