Indo-Iranian languages

Development

Indo-Iranian is a part of the Satem areal also including the Balto-Slavic languages, Albanian and Armenian. In these languages PIE "palatovelar" consonants (probably originally the plain velars) were characteristically fronted to postalveolar affricates *c, *jʰ, *j, while the PIE labiovelars and "plain velars" (probably originally uvulars) were then merged as new velars *k, *gʰ, *g.

The Law of Palatals introduced to Indo-Iranian a new set of palatal consonants: *k > *ĉ, *g⁽ʰ) > *ĵ⁽ʰ⁾, when preceding the original front vowels *e, *i.

The most characteristic feature of Indo-Iranian may be its simplification of the PIE vowel system: *e, *o, *a, *n̥, *m̥ were all merged as simple *a. This phonemicized the previous set of palatal consonants. — On the other hand, late PIE *ə (the vocalized allophone of laryngeals) was instead raised to *i.

Subgrouping

The Iranian group was originally set up to contain all members of Indo-Iranian not derivable from Sanskrit. However, only a small number of isoglosses defining Iranian as a whole have been proposed, and most of these isoglosses appear to "leak" in some way or the other (appearing reversed or absent in a number of descendants). By now at least the Nuristani languages are widely recognized as a separate group.

An agnostic account might recognize as many as six branches of Indo-Iranian:

• Sakan, a small northwestern group of three languages: †Khotanese, †Tumshuqese, and Wakhi.
• Persid (Southwestern Iranian), comprising Old Persian and its descendants.
• Narrow Iranian consists of most languages traditionally considered Iranian.
• Nuristani, spoken in the Hindu Kush mountains.
• Dardic, spoken also in the Hindu Kush mountains. Usually considered closely affiliated to Narrow Indic.
• Narrow Indic consists of most languages traditionally considered Indic (Indo-Aryan).

Phonetical isoglosses connecting these groups include:

• The two PII voiced series (traditionally reconstructed as plain voiced vs. voiced aspirate) merge everywhere except in Narrow Indic. This change is shared also with Balto-Slavic and Albanian.
• The PII clusters *ćw, *jw undergo different characteristic development in each of the traditional "Iranian" branches:
  • Sakan: *ćw, *jw > *ś, *ź
  • Persid: *ćw, *jw > *s, *z
  • Narrow Iranian + Nuristani: *ćw, *jw > *sp, *zb
• In other positions the PII postalveolars *ć, *j are fronted to dental affricates *ts, *dz in all varieties other than Dardic and Narrow Indic. The change must be dated as posterior to the previous changes, and is therefore inapplicable as evidence for a common Iranian or Iranian-Nuristani group.
  • In Persid these are furthermore fronted to *θ and *ð > *d.
  • In Narrow Iranian as well as Sakan these are deaffricated to *s, *z.
• Dardic and Narrow Indic merge the PII postalveolars with the PII palatals *ĉ *ĵ⁽ʰ⁾, with the exception of *ć; this yields Narrow Indic *ś.
• In Persid + most of Narrow Iranian (but absent from Balochi), PII *p *t *k are spirantized to *f *θ *x preceding a consonant.
• Sakan, Dardic and Narrow Indic develop a series of voiceless aspirates from PIE (and PII) clusters of voiceless stop + *h₂. Originally this was posited as a common Indo-Iranian innovation, though one would have to assume later lenition to voiceless fricatives in parts of Iranian (better handled as a part of the previous soundlaw), and loss of aspiration altogether in Nuristani.