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.
| PIE |
PII |
Sanskrit |
Avestan |
Latin |
|
| *k̂m̥tóm |
*ĉatám |
śatám |
satəm |
centum |
"hundred" |
| *ĝónu |
*ĵā́nu |
jā́nu |
zānu |
genu |
"knee" |
| *ĝʰéi-mn̥ |
*ĵʰimá- |
himá- |
zima- |
hiems |
"winter" / "snow" |
| *kʷó- |
*ká- |
ká- |
kō |
quis |
"who?, what?" |
| *gʷou- |
*gau- |
go |
gau- |
bos, bovis |
"cow" |
| *gʷʰormó- |
*gʰarmá- |
gharmá- |
garəma- |
formus |
"warmth, heat" |
- The PIE syllabic liquids *l̥, *r̥ merge as *r̥.
| PIE |
PII |
Sanskrit |
Avestan |
Latin |
|
| *wĺ̥kʷo- |
*wŕ̥ka- |
*vŕ̥ka- |
vəhrka- |
lupus |
"wolf" |
- The PIE syllabic nasals *m̥ *n̥ merge with *a.
| PIE |
PII |
Sanskrit |
Avestan |
Latin |
|
| *k̂m̥tóm |
*ĉatám |
śatám |
satəm |
centum |
"hundred" |
| *mn̥tó- |
*matá |
matá- |
|
mens, mentis |
"thinking" |
- Bartholomae's law: an aspirate immediately followed by a voiceless consonant becomes voiced stop + voiced aspirate. In addition, dʰ + t > dzdʰ.
| PIE |
PII |
Sanskrit |
Avestan |
|
| *ubʰto- |
*ubdʰa- |
|
ubdaēna |
"woven" / "made of woven material" |
| *urdʰto- |
*urdzdʰa- |
vr̥ddʰá- |
vrzda- |
"complete/mature" |
| *augʰ-tá- |
*augdʰá- |
*óhate |
*augda |
"he said" |
- The Ruki rule: *s is retracted to *š when immediately following *r *r̥ *u *k or *i. Its allophone *z likewise becomes *ž.
| PIE |
PII |
Sanskrit |
Avestan |
|
| *wers- |
*warš- |
varṣman- |
|
"summit" |
| *pr̥sto- |
*pr̥šta- |
pr̥ṣṭhá- |
paršta |
"back" / "backbone" |
| *ǵeus- |
*ĵauš- |
joṣati |
zaošō |
"taste" |
| *kʷsep- |
*kšap- (< *ksep) |
kṣāp |
xšap |
"darkness" |
| *wis- |
*wiš- |
viṣa- |
viša- |
"poison" |
| *nisdo- |
*nižda- |
nīḍa- |
|
"nest" |
- Before a dental occlusive, *ĉ becomes *š and *ĵ becomes *ž. *ĵʰ also becomes *ž, with aspiration of the occlusive.
| PIE |
pre-PII |
PII |
Sanskrit |
Avestan |
|
| *h₂ok̂tṓ |
*oĉtṓ |
*aštā́ |
aṣṭaú |
ašta |
"eight" |
| *h₃mr̥ĝt- |
*mr̥ĵd- |
*mr̥žd- |
mr̥ḍīká- |
mərəžḍīka |
"wiped away" / "pardon" |
| *uĝʰtó- |
*uĵʰtó- |
*uždʰá- |
ūḍhá- |
|
"carried" |
- The sequence *ĉs was simplified to *šš.
| PIE |
pre-PII |
PII |
Sanskrit |
Avestan |
Latin |
|
| *h₂ék̂s- |
*áĉs- |
*ášš- |
ákṣa- |
aši- |
axis |
"shoulder" / "axle" |
- The "second palatalization" or "law of palatals": *k *g *gʰ develop palatal allophones *č *ǰ *ǰʰ before the front vowels *i, *e.
| PIE |
pre-PII |
PII |
Sanskrit |
Avestan |
|
| *kʷe |
*ke |
*ča |
ca |
ča |
"and" |
| *gʷíh₃weti |
*gíh₃weti |
*ǰī́wati |
jī́vati |
jvaiti |
"lives" |
| *gʷʰénti |
*gʰénti |
*ǰʰánti |
hánti |
jainti |
"slays" |
- Brugmann's law: *o in an open syllable lengthens to *ō.
| PIE |
pre-PII |
PII |
Sanskrit |
Avestan |
Latin |
|
| *deh₃tór-m |
*deh₃tṓr-m |
*dātā́ram |
dātā́ram |
dātāram |
dator |
"giver" (acc. sg.) |
- 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 |
|
| *kʷe |
*ča (< *če) |
ca |
ča |
"and" |
| *gʷʰormó- |
*gʰarmá- |
gharmá- |
garəma- |
"heat" |
| *bʰréh₂tēr |
*bʰrā́tār |
bhrā́tā |
brātā |
"brother" |
| *wōkʷs |
*wākš |
vāk |
vāxš |
"voice" |
- In certain positions, laryngeals were vocalized to *i. This preceded the second palatalization.
- Following a consonant, and preceding a consonant cluster
| PIE |
PII |
Sanskrit |
Avestan |
|
| *ph₂trei |
*pitrai |
pitre |
piθrai |
"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.
| PIE |
PII |
Sanskrit |
Avestan |
|
| *ph₂tér |
*pHtā́ |
pitā́ |
ptā |
"father" (nominative singular) |
- According to Lubotsky's Law, *H disappeared when followed by a voiced nonaspirated stop and another consonant:
| PIE |
PII |
Sanskrit |
Avestan |
|
| *bʰeh₂g- |
*bʰag- ( < *bʰaHg- ) |
bʰag- |
baxša |
"distribute" |