Proto-Iranian language

Proto-Iranian or Proto-Iranic is the reconstructed proto-language of the Iranian languages branch of Indo-European language family and thus the ancestor of the Iranian languages such as Persian, Pashto, Sogdian, Zazaki, Ossetian, Mazandarani, Kurdish, Talysh and others. Its speakers, the hypothetical Proto-Iranians, are assumed to have lived in the 2nd millennium BC and are usually connected with the Andronovo archaeological horizon (see Indo-Iranians).

Proto-Iranian was a satem language descended from the Proto-Indo-Iranian language, which in turn, came from the Proto-Indo-European language. It was likely removed less than a millennium from the Avestan language, and less than two millennia from Proto-Indo-European.

Skjærvø postulates that there were at least four dialects that initially developed out of Proto-Iranian, two of which are attested by texts:

Note that different terminology is used for the modern languages: Ossetian has often been classified as a "Northeast Iranian" language, while "Northwest Iranian" usually refers to languages to the northwest of Persian, such as Zaza or the Caspian languages.

The term Old Iranian refers to the stage in Iranian history represented by the earliest written languages: Avestan and Old Persian. These two languages are usually considered to belong to different main branches of Iranian, and many of their similarities are found also in the other Iranian languages. Regardless, there are many arguments that many of these Old Iranian features may not have occurred yet in Proto-Iranian, and they may have instead spread across an Old Iranian dialect continuum already separated in dialects (see Wave theory). Additionally, most Iranian languages cannot be derived from either attested Old Iranian language: numerous unwritten Old Iranian dialects must have existed, whose descendants surface in the written record only later.

The Proto-Indo-European laryngeal consonants are likely to have been retained quite late in the Indo-Iranian languages in at least some positions. However, the syllabic laryngeal (*H̥) was deleted in non-initial syllables.

This change is found widely across the Iranian languages, indeed Indo-Iranian as a whole: it appears also in Vedic Sanskrit. Avestan has no **/l/ phoneme at all. Regardless many words, for which the other Indo-European languages indicate original *l, still show /l/ in several Iranian languages, including New Persian, Kurdish and Zazaki. These include e.g. Persian lab 'lip', līz- 'to lick', gulū 'throat' (compare e.g. Latin gula); Zazaki lü 'fox' (compare e.g. Latin vulpēs). This preservation is however not systematic, and likely has been mostly diminished through interdialectal loaning of r-forms, and in some cases extended by the loaning of words from smaller western Iranian languages into Persian.

Exactly, this debuccalization occurred when not preceded *k, *n, *p, *t or followed *t (which otherwise retained as *s). This change occurs in all Iranian languages.