|Central Asia, northwestern South Asia, Caucasus. Historically in Scythia and Sarmatia.|
The Eastern Iranian languages are a subgroup of the Iranian languages emerging in Middle Iranian times (from c. the 4th century BC). The Avestan language is often classified as early Eastern Iranian. The largest living Eastern Iranian language is Pashto, with some 50 million speakers between the Hindu Kush mountains in Afghanistan and the Indus River in Pakistan. As opposed to the Middle Western Iranian dialects, the Middle Eastern Iranian preserves word-final syllables.
Most living Eastern Iranian languages are spoken in a contiguous area, in eastern Afghanistan as well as the adjacent parts of western Pakistan, Gorno-Badakhshan Autonomous Province of eastern Tajikistan, and the far west of Xinjiang region of China. There are also two living members in widely separated areas: the Yaghnobi language of northwestern Tajikistan (descended from Sogdian), and the Ossetic language of the Caucasus (descended from Scytho-Sarmatian). These are remnants of a vast ethno-linguistic continuum that stretched over most of Central Asia, Eastern Europe, and parts of the Caucasus, and West Asia in the 1st millennium BC, otherwise known as Scythia. The large Eastern Iranian continuum in Eastern Europe would continue up to including the 4th century AD, with the successors of the Scythians, namely the Sarmatians.
With Greek presence in Central Asia, some of the easternmost of these languages were recorded in their Middle Iranian stage (hence the "Eastern" classification), while almost no records of the Scytho-Sarmatian continuum stretching from Kazakhstan west across the Pontic steppe to Ukraine have survived. Some authors find that the Eastern Iranian people had an influence on Russian folk culture.
Middle Persian/Dari spread around the Oxus River region, Afghanistan, and Khorasan after the Arab conquests and during Islamic-Arab rule. The replacement of the Pahlavi script with the Arabic script in order to write the Persian language was done by the Tahirids in 9th century Khorasan. The Persian Dari language spread and led to the extinction of Eastern Iranic languages like Bactrian and Khorezmian, with only a tiny amount of Sogdian descended Yaghnobi speakers remaining among the now Persian speaking Tajik population of Central Asia, due to the fact that the Arab-Islamic army which invaded Central Asia also included some Persians who later governed the region like the Samanids. Persian was rooted into Central Asia by the Samanids.
Eastern Iranian remains a single dialect continuum subject to common innovation. Traditional branches, such as "Northeastern", as well as Eastern Iranian itself, are better considered language areas rather than genetic groups.
The languages are as follows:
Avestan+ (c. 1000 - 7th century BC) is commonly classified as Eastern, but is not assigned to a branch in this classification.
The Eastern Iranian area has been affected by widespread sound changes, e.g. t > ts.
Common to most Eastern Iranian languages is a particularly widespread lenition of the voiced stops *b, *d, *g. Between vowels, these have been lenited also in most Western Iranian languages, but in Eastern Iranian, spirantization also generally occurs in the word-initial position. This phenomenon is however not apparent in Avestan, and remains absent from Ormuri-Parachi.
A series of spirant consonants can be assumed to have been the first stage: *b > *?, *d > *ð, *g > *?. The voiced velar fricative /?/ has mostly been preserved. The labial member has been well-preserved too, but in most languages has shifted from a voiced bilabial fricative /?/ to the voiced labiodental fricative /v/. The dental member has proved the most unstable: while a voiced dental fricative /ð/ is preserved in some Pamir languages, it has in e.g. Pashto and Munji lenited further to /l/. On the other hand, in Yaghnobi and Ossetian, the development appears to have been reversed, leading to the reappearance of a voiced stop /d/. (Both languages have also shifted earlier *? > /t/.)
|ten||dasa||las||los / d?1||dos||?as||?is||d?s||das||das||dæs|
The consonant clusters *ft and *xt have also been widely lenited, though again excluding Ormuri-Parachi, and possibly Yaghnobi.
The neighboring Indo-Aryan languages have exerted a pervasive external influence on the closest neighbouring Eastern Iranian, as it is evident in the development in the retroflex consonants (in Pashto, Wakhi, Sanglechi, Khotanese, etc.) and aspirates (in Khotanese, Parachi and Ormuri). A more localized sound change is the backing of the former retroflex fricative [?], to x? [x] or to x [?], found in the Shughni-Yazgulyam branch and certain dialects of Pashto. E.g. "meat": ?ut in Wakhi and ?waa in Southern Pashto, but changes to guxt in Shughni, ?wax?a in Central Pashto and ?waxa in Northern Pashto.