In addition to the vowels, *H, and *r̥ could function as the syllabic core.
Two palatal series
Proto-Indo-Iranian is hypothesized to contain two series of stops or affricates in the palatal to postalveolar region.[2] The phonetic nature of this contrast is not clear, and hence they are usually referred to as the "primary"/"first" series (*ĉ *ĵ *ĵʰ, continuing Proto-Indo-European palatovelar *ḱ *ǵ *ǵʰ) and the "second(ary)" series (*č *ǰ *ǰʰ, continuing Proto-Indo-European plain and labialized velars *k⁽ʷ⁾ *g⁽ʷ⁾ *gʰ⁽ʷ⁾ in palatalizing contexts).
The following table shows the most common reflexes of the two series (Proto-Iranian is the hypothetical ancestor to the Iranian languages, including Avestan and Old Persian):[3][4]
PII
Sanskrit
Proto-Iranian
Avestan
Old Persian
Nuristani
*ĉ
ś ([ɕ])
*ts
s
θ
ċ ([ts]) / š
*ĵ
j ([ɟ])
*dz
z
d
j ([dz]) / z
*ĵʰ
h ([ɦ])
*č
c
*č
č
č
č
*ǰ
j ([ɟ])
*ǰ
ǰ
ǰ
ǰ / ž
*ǰʰ
h ([ɦ])
Laryngeal
Proto-Indo-European is usually hypothesized to have had three to four laryngeal consonants, each of which could occur in either syllabic or non-syllabic position. In Proto-Indo-Iranian, the laryngeals merged as one phoneme /*H/. Beekes suggests that some instances of this /*H/ survived into Avestan as unwritten glottal stops.[5]
Accent
Like Proto-Indo-European and Vedic Sanskrit (and also Avestan, though it was not written down[6]), Proto-Indo-Iranian had a pitch accent, indicated by an acute accent over the accented vowel.
Historical phonology
The most distinctive phonological change separating Proto-Indo-Iranian from Proto-Indo-European is the collapse of the ablauting vowels *e, *o, *a into a single vowel, Proto-Indo-Iranian *a (but see Brugmann's law). Grassmann's law, Bartholomae's law, and the Ruki sound law were also complete in Proto-Indo-Iranian.
A fuller list of some of the hypothesized sound changes from Proto-Indo-European to Proto-Indo-Iranian follows:
The Satem shift, consisting of two sets of related changes. The PIE palatals *k̂ *ĝ *ĝʰ are fronted or affricated, eventually resulting in PII *ĉ, *ĵ, *ĵʰ, while the PIE labiovelars *kʷ *gʷ *gʷʰ merge with the velars *k *g *gʰ.[7]
PIE
PII
Sanskrit
Avestan
Latin
*k̂m̥tóm
*ĉatám
śatám
satəm
centum
"hundred"
*ĝónu
*ĵā́nu
jā́nu
zānu
genū
"knee"
*ĝʰéi-mn̥
*ĵʰimá-
himá-
zima-
hiems
"winter" / "snow"
*kʷó-
*ká-
ká-
kō
quis
"who?, what?"
*gʷou-
*gau-
go
gau-
bōs, bov-
"cow"
*gʷʰormó-
*gʰarmá-
gharmá-
garəma-
formus
"warmth, heat"
The PIE syllabic liquids *l̥, *r̥ merge as *r̥.[8]
The vowels *e *o merge with *a. Similarly, *ē, *ō merge with *ā. This has the effect of giving full phonemic status to the second palatal series *č *ǰ *ǰʰ.
PIE
PII
Sanskrit
Avestan
Latin
*kʷe
*ča (< *če)
ca
ča
-que
"and"
*gʷʰormó-
*gʰarmá-
gharmá-
garəma-
formus
"heat"
*bʰréh₂tēr
*bʰrā́tār
bhrā́tā
brātā
frāter
"brother"
*wōkʷs
*wākš
vāk
vāxš
vōx
"voice"
In certain positions, laryngeals were vocalized to *i. This preceded the second palatalization.[13][14]
Following a consonant, and preceding a consonant cluster
PIE
PII
Sanskrit
Avestan
Latin
*ph₂trei
*pitrai
pitre
piθrai
patrī
"father" (dative singular)
Following a consonant and word-final
PIE
PII
Sanskrit
Avestan
*-medʰh₂
*-madʰi
-mahi
-madi
(1st person plural middle ending)
The Indo-European laryngeals all merged into one phoneme *H, which may have been a glottal stop. This was probably contemporary with the merging of *e and *o with *a.[15]
PIE
PII
Sanskrit
Avestan
Latin
*ph₂tér
*pHtā́
pitā́
ptā
pater
"father" (nominative singular)
According to Lubotsky's Law, *H disappeared when followed by a voiced nonaspirated stop and another consonant:[16]
PIE
PII
Sanskrit
Avestan
*bʰeh₂g-
*bʰag- ( < *bʰaHg- )
bʰag-
baxša
"distribute"
Subsequent sound changes
Among the sound changes from Proto-Indo-Iranian to Indo-Aryan is the loss of the voiced sibilant *z, among those to Iranian is the de-aspiration of the PIE voiced aspirates.
Template:PIE-OInd-Av
Alexander Lubotsky, "The Indo-Iranian substratum" in Early Contacts between Uralic and Indo-European, ed. Carpelan et al., Helsinki (2001).
Asko Parpola, 'The formation of the Aryan branch of Indo-European', in Blench and Spriggs (eds), Archaeology and Language III, London and New York (1999).