Persian is classified as a member of the Southwestern subgroup within Western Iranian along with Lari, Kumzari, and Luri.
From about the 9th century onward, as Middle Persian was on the threshold of becoming New Persian, the older form of the language came to be erroneously called Pahlavi, which was actually but one of the writing systems used to render both Middle Persian as well as various other Middle Iranian languages.
That writing system had previously been adopted by the Sassanids (who were Persians, i.e.
Radio Free Europe/Radio Liberty also includes a Tajik service and an Afghan (Dari) service.
This is also the case for the American Association of Teachers of Persian, The Centre for Promotion of Persian Language and Literature, and many of the leading scholars of the Persian language.
Persian is an Iranian language belonging to the Indo-Iranian branch of the Indo-European family of languages.