Editing Indo-European languages (section)

=== Sound changes ===
{{Main|Indo-European sound laws}}
As speakers of Proto-Indo-European (PIE) dispersed, the language's sound system diverged as well, changing according to various [[sound law]]s evidenced in the [[daughter language]]s.

PIE is normally reconstructed with a complex system of 15 [[stop consonant]]s, including an unusual three-way [[phonation]] ([[voice (phonetics)|voicing]]) distinction between [[voiceless]], [[voiced]] and "[[voiced aspirated]]" (i.e. [[breathy voiced]]) stops, and a three-way distinction among [[velar consonant]]s (''k''-type sounds) between "palatal" ''ḱ ǵ ǵh'', "plain velar" ''k g gh'' and [[Labialized velar consonant|labiovelar]] ''kʷ gʷ gʷh''. (The correctness of the terms ''palatal'' and ''plain velar'' is disputed; see [[Proto-Indo-European phonology]].) All daughter languages have reduced the number of distinctions among these sounds, often in divergent ways.

As an example, in [[English language|English]], one of the [[Germanic language]]s, the following are some of the major changes that happened:
{{ordered list
|1= As in other [[centum]] languages, the "plain velar" and "palatal" stops merged, reducing the number of stops from 15 to 12.
|2= As in the other Germanic languages, the [[Germanic sound shift]] changed the realization of all stop consonants, with each consonant shifting to a different one:
: {{PIE|bʰ}} → {{PIE|b}} → {{PIE|p}} → {{PIE|f}}
: {{PIE|dʰ}} → {{PIE|d}} → {{PIE|t}} → {{PIE|θ}}
: {{PIE|gʰ}} → {{PIE|g}} → {{PIE|k}} → {{PIE|x}} (Later initial {{PIE|x}} →{{PIE|h}})
: {{PIE|gʷʰ}} → {{PIE|gʷ}} → {{PIE|kʷ}} → {{PIE|xʷ}} (Later initial {{PIE|xʷ}} →{{PIE|hʷ}})
Each original consonant shifted one position to the right. For example, original {{PIE|dʰ}} became {{PIE|d}}, while original {{PIE|d}} became {{PIE|t}} and original {{PIE|t}} became {{PIE|θ}} (written ''th'' in English). This is the original source of the English sounds written ''f'', ''th'', ''h'' and ''wh''. Examples, comparing English with Latin, where the sounds largely remain unshifted:
:For PIE ''p'': ''piscis'' vs. ''fish''; ''pēs, pēdis'' vs. ''foot''; ''pluvium'' "rain" vs. ''flow''; ''pater'' vs. ''father''
:For PIE ''t'': ''trēs'' vs. ''three''; ''māter'' vs. ''mother''
:For PIE ''d'': ''decem'' vs. ''ten''; ''pēdis'' vs. ''foot''; ''quid'' vs. ''what''
:For PIE ''k'': ''centum'' vs. ''hund(red)''; ''capere'' "to take" vs. ''have''
:For PIE ''kʷ'': ''quid'' vs. ''what''; ''quandō'' vs. ''when''
|3= Various further changes affected consonants in the middle or end of a word:
* The voiced stops resulting from the sound shift were softened to voiced [[fricatives]] (or perhaps the sound shift directly generated fricatives in these positions).
* [[Verner's law]] also turned some of the voiceless fricatives resulting from the sound shift into voiced fricatives or stops. This is why the ''t'' in Latin ''centum'' ends up as ''d'' in ''hund(red)'' rather than the expected ''th''.
* Most remaining ''h'' sounds disappeared, while remaining ''f'' and ''th'' became voiced. For example, Latin ''decem'' ends up as ''ten'' with no ''h'' in the middle (but note ''taíhun'' "ten" in [[Gothic language|Gothic]], an archaic Germanic language). Similarly, the words ''seven'' and ''have'' have a voiced ''v'' (compare Latin ''septem'', ''capere''), while ''father'' and ''mother'' have a voiced ''th'', although not spelled differently (compare Latin ''pater'', ''māter'').
}}

None of the daughter-language families (except possibly [[Anatolian languages|Anatolian]], particularly [[Luvian]]) reflect the plain velar stops differently from the other two series, and there is even a certain amount of dispute whether this series existed at all in PIE. The major distinction between [[Centum-satem isogloss|''centum'' and ''satem'']] languages corresponds to the outcome of the PIE plain velars:
* The "central" ''satem'' languages ([[Indo-Iranian languages|Indo-Iranian]], [[Balto-Slavic]], [[Albanian language|Albanian]], and [[Armenian language|Armenian]]) reflect both "plain velar" and labiovelar stops as plain velars, often with secondary [[Palatalization (sound change)|palatalization]] before a [[front vowel]] (''e i ē ī''). The "palatal" stops are palatalized and often appear as [[sibilant]]s (usually but not always distinct from the secondarily palatalized stops).
* The "peripheral" ''centum'' languages ([[Germanic languages|Germanic]], [[Italic languages|Italic]], [[Celtic languages|Celtic]], [[Greek language|Greek]], [[Anatolian languages|Anatolian]] and [[Tocharian language|Tocharian]]) reflect both "palatal" and "plain velar" stops as plain velars, while the labiovelars continue unchanged, often with later reduction into plain [[labial consonant|labial]] or [[velar consonant]]s.

The three-way PIE distinction between voiceless, voiced and voiced aspirated stops is considered extremely unusual from the perspective of [[linguistic typology]]—particularly in the existence of voiced aspirated stops without a corresponding series of voiceless aspirated stops. None of the various daughter-language families continue it unchanged, with numerous "solutions" to the apparently unstable PIE situation:
* The [[Indo-Aryan language]]s preserve the three series unchanged but have evolved a fourth series of voiceless aspirated consonants.
* The [[Iranian language]]s probably passed through the same stage, subsequently changing the aspirated stops into fricatives.
* [[Greek language|Greek]] converted the voiced aspirates into voiceless aspirates.
* [[Italic languages|Italic]] probably passed through the same stage, but reflects the voiced aspirates as voiceless fricatives, especially ''f'' (or sometimes plain voiced stops in [[Latin]]).
* [[Celtic languages|Celtic]], [[Balto-Slavic]], [[Anatolian languages|Anatolian]], and [[Albanian language|Albanian]] merge the voiced aspirated into plain voiced stops.
* [[Germanic languages|Germanic]] and [[Armenian language|Armenian]] change all three series in a [[chain shift]] (e.g. with ''bh b p'' becoming ''b p f'' (known as ''[[Grimm's law]]'' in Germanic)).

Among the other notable changes affecting consonants are:
* The [[Ruki sound law]] (''s'' becomes {{IPA|/ʃ/}} before ''r, u, k, i'') in the ''[[satem]]'' languages.
* Loss of prevocalic ''p'' in [[Proto-Celtic]].
* Development of prevocalic ''s'' to ''h'' in [[Proto-Greek]], with later loss of ''h'' between vowels.
* [[Verner's law]] in [[Proto-Germanic]].
* [[Grassmann's law]] (dissimilation of aspirates) independently in Proto-Greek and Proto-Indo-Iranian.

The following table shows the basic outcomes of PIE consonants in some of the most important daughter languages for the purposes of reconstruction. For a fuller table, see [[Indo-European sound laws]].

{| class=wikitable style="white-space: nowrap;"
|+ Proto-Indo-European consonants and their [[Reflex (linguistics)|reflexes]] in selected Indo-European daughter languages
! rowspan=2|PIE !! rowspan=2|[[Sanskrit|Skr.]] !! rowspan=2|[[Old Church Slavonic|O.C.S.]] !! rowspan=2|[[Lithuanian language|Lith.]] !! rowspan=2|[[Greek language|Greek]] !! rowspan=2|[[Latin]] !! rowspan=2|[[Old Irish]] !! rowspan=2|[[Gothic language|Gothic]] !! rowspan=2|English !! colspan=6|Examples
!
|- align=center
! PIE !! Eng. !! [[Sanskrit|Skr.]] !! [[Ancient Greek|Gk.]] !! [[Latin|Lat.]] !! [[Lithuanian language|Lith.]] etc.
![[Persian language|Prs]].
|- align=center
!'''{{PIE|*p}}'''
|'''{{PIE|p}}'''; '''{{PIE|ph}}'''<sup>H</sup>
| colspan="4"|'''{{PIE|p}}'''
|'''{{PIE|Ø}}''';<br />'''{{PIE|ch}}'''<sup>T</sup> {{IPA|[x]}}
|'''{{PIE|f}}''';<br />`-'''{{PIE|b}}'''- {{IPA|[β]}}
|'''{{PIE|f}}''';<br />-'''{{PIE|v/f}}'''-
|''*pṓds ~ *ped-'' || ''foot'' || ''pád-'' || ''poús (podós)'' || ''pēs (pedis)'' || ''pãdas''
|Pi''á''de
|- align=center
!'''{{PIE|*t}}'''
|'''{{PIE|t}}'''; '''{{PIE|th}}'''<sup>H</sup>
| colspan="4"|'''{{PIE|t}}'''
|'''{{PIE|t}}''';<br />-'''{{PIE|th}}'''- {{IPA|[θ]}}
|'''{{PIE|þ}}''' {{IPA|[θ]}};<br />`-'''{{PIE|d}}'''- {{IPA|[ð]}};<br />'''{{PIE|t}}'''<sup>T-</sup>
|'''{{PIE|th}}''';<br />`-'''{{PIE|d}}'''-;<br />'''{{PIE|t}}'''<sup>T-</sup>
|''*tréyes'' || ''three'' || ''tráyas''|| ''treĩs'' || ''trēs'' || ''trỹs''
|thri (old Persian)
|- align=center
!'''{{PIE|*ḱ}}'''
|'''{{PIE|ś}}''' {{IPA|[ɕ]}}
|'''{{PIE|s}}'''
|'''{{PIE|š}}''' {{IPA|[ʃ]}}
| rowspan="2"|'''{{PIE|k}}'''
| rowspan="2"|'''{{PIE|c}}''' {{IPA|[k]}}
| rowspan="4"|'''{{PIE|c}}''' {{IPA|[k]}};<br />-'''{{PIE|ch}}'''- {{IPA|[x]}}
| rowspan="2"|'''{{PIE|h}}''';<br />`-'''{{PIE|g}}'''- {{IPA|[ɣ]}}
| rowspan="2"|'''{{PIE|h}}''';<br />-'''{{PIE|Ø}}'''-;<br />`-'''{{PIE|y}}'''-
|''*ḱm̥tóm'' || ''hund(red)'' || ''śatám'' || ''he-katón'' || ''centum'' || ''šimtas''
|sad
|- align=center
!'''{{PIE|*k}}'''
| rowspan="3"|'''{{PIE|k}}'''; '''{{PIE|c}}'''<sup>E</sup> {{IPA|[tʃ]}};<br />'''{{PIE|kh}}'''<sup>H</sup>
| rowspan="3"|'''{{PIE|k}}''';<br />'''{{PIE|č}}'''<sup>E</sup> {{IPA|[tʃ]}};<br />'''{{PIE|c}}'''<sup>E'</sup> {{IPA|[ts]}}
| rowspan="3"|'''{{PIE|k}}'''
|''*kreuh₂''<br /> "raw meat" || OE ''hrēaw''<br /> ''raw'' || ''kravíṣ-'' || ''kréas'' || ''cruor'' || ''kraûjas''
|xore''š''
|- align=center
!rowspan=2|'''{{PIE|*kʷ}}'''
|rowspan=2|'''{{PIE|p}}''';<br />'''{{PIE|t}}'''<sup>E</sup>;<br />'''{{PIE|k}}'''<sup>(u)</sup>
|rowspan=2|'''{{PIE|qu}}''' {{IPA|[kʷ]}};<br />'''{{PIE|c}}'''<sup>(O)</sup> {{IPA|[k]}}
|rowspan=2|'''{{PIE|ƕ}}''' {{IPA|[ʍ]}};<br />`-'''{{PIE|gw/w}}'''-
|rowspan=2|'''{{PIE|wh}}''';<br />`-'''{{PIE|w}}'''-
| ''*kʷid, kʷod'' || ''what'' || ''kím'' || ''tí'' || ''quid, quod'' ||''kas'', ''kad''
|ce, ci
|- align=center
| ''*kʷekʷlom'' || ''wheel'' || ''cakrá-'' || ''kúklos'' || || ''kãklas''
|carx
|- align=center
!'''{{PIE|*b}}'''
|'''{{PIE|b}}'''; '''{{PIE|bh}}'''<sup>H</sup>
| colspan="4"|'''{{PIE|b}}'''
|'''{{PIE|b}}''' {{IPA|[b]}};<br />-'''{{IPA|[β]}}'''-
| colspan="2"|'''{{PIE|p}}'''
|- align=center
!'''{{PIE|*d}}'''
|'''{{PIE|d}}'''; '''{{PIE|dh}}'''<sup>H</sup>
| colspan="4"|'''{{PIE|d}}'''
|'''{{PIE|d}}''' {{IPA|[d]}};<br />-{{IPA|[ð]}}-
| colspan="2"|'''{{PIE|t}}'''
| ''*déḱm̥(t)'' || ''ten'',<br />[[Gothic language|Goth.]] ''taíhun'' || ''dáśa'' || ''déka'' || ''decem'' || ''dẽšimt''
|dah
|- align=center
!'''{{PIE|*ǵ}}'''
|'''{{PIE|j}}''' {{IPA|[dʒ]}};<br />'''{{PIE|h}}'''<sup>H</sup> {{IPA|[ɦ]}}
|'''{{PIE|z}}'''
|'''{{PIE|ž}}''' {{IPA|[ʒ]}}
| colspan="2" rowspan="2"|'''{{PIE|g}}'''
| rowspan="2"|'''{{PIE|g}}''' {{IPA|[ɡ]}};<br />-{{IPA|[ɣ]}}-
| rowspan="2"|'''{{PIE|k}}'''
| rowspan="2"|'''{{PIE|c / k}}''';<br />'''{{PIE|ch}}'''<sup>E'</sup>
| ''*ǵénu, *ǵnéu-'' || OE ''cnēo''<br /> ''knee'' || ''jā́nu'' || ''gónu'' || ''genu'' ||
|z''ánu''
|- align=center
!'''{{PIE|*g}}'''
| rowspan="2"|'''{{PIE|g}}''';<br /> '''{{PIE|j}}'''<sup>E</sup> {{IPA|[dʒ]}};<br />'''{{PIE|gh}}'''<sup>H</sup>;<br /> '''{{PIE|h}}'''<sup>H,E</sup> {{IPA|[ɦ]}}
| rowspan="2"|'''{{PIE|g}}''';<br />'''{{PIE|ž}}'''<sup>E</sup> {{IPA|[ʒ]}};<br />'''{{PIE|dz}}'''<sup>E'</sup>
| rowspan="2"|'''{{PIE|g}}'''
|''*yugóm'' || ''yoke'' || ''yugám'' || ''zugón'' || ''iugum'' || ''jùngas''
|yugh
|- align=center
!'''{{PIE|*gʷ}}'''
|'''{{PIE|b}}''';<br />'''{{PIE|d}}'''<sup>e</sup>;<br />'''{{PIE|g}}'''<sup>(u)</sup>
|'''{{PIE|u}}''' {{IPA|[w > v]}};<br />'''{{PIE|gu}}'''<sup>n−</sup> {{IPA|[ɡʷ]}}
| rowspan="2"|'''{{PIE|b}}''' {{IPA|[b]}};<br />-{{IPA|[β]}}-
|'''{{PIE|q}}''' {{IPA|[kʷ]}}
|'''{{PIE|qu}}'''
| ''*gʷīw-'' || ''quick''<br />"alive" || ''jīvá-'' || ''bíos'',<br />''bíotos'' || ''vīvus'' || ''gývas''
|ze-
|- align=center
!'''{{PIE|*bʰ}}'''
|'''{{PIE|bh}}''';<br /> '''{{PIE|b}}'''<sup>..Ch</sup>
| colspan="2"|'''{{PIE|b}}'''
|'''{{PIE|ph}}''';<br /> '''{{PIE|p}}'''<sup>..Ch</sup>
|'''{{PIE|f}}'''-;<br />'''{{PIE|b}}'''
|'''{{PIE|b}}''' {{IPA|[b]}};<br />-{{IPA|[β]}}-;<br />-'''{{PIE|f}}'''
|'''{{PIE|b}}''';<br />-'''{{PIE|v/f}}'''-<sup>(rl)</sup>
| ''*bʰéroh₂'' || ''bear'' "carry" || ''bhar-'' || ''phérō'' || ''ferō'' || [[Old Church Slavonic|OCS]] ''berǫ''
|bar-
|- align=center
!'''{{PIE|*dʰ}}'''
|'''{{PIE|dh}}''';<br /> '''{{PIE|d}}'''<sup>..Ch</sup>
| colspan="2"|'''{{PIE|d}}'''
|'''{{PIE|th}}''';<br /> '''{{PIE|t}}'''<sup>..Ch</sup>
|'''{{PIE|f}}'''-;<br />'''{{PIE|d}}''';<br />'''{{PIE|b}}'''<sup>(r),l,u-</sup>
|'''{{PIE|d}}''' {{IPA|[d]}};<br />-{{IPA|[ð]}}-
|'''{{PIE|d}}''' {{IPA|[d]}};<br />-{{IPA|[ð]}}-;<br />-'''{{PIE|þ}}'''
|'''{{PIE|d}}'''
|''*dʰwer-, dʰur-'' || ''door'' || ''dvā́raḥ'' || ''thurā́'' || ''forēs'' || ''dùrys''
|dar
|- align=center
!'''{{PIE|*ǵʰ}}'''
|'''{{PIE|h}}''' {{IPA|[ɦ]}};<br /> '''{{PIE|j}}'''<sup>..Ch</sup>
|'''{{PIE|z}}'''
|'''{{PIE|ž}}''' {{IPA|[ʒ]}}
| rowspan="2"|'''{{PIE|kh}}''';<br /> '''{{PIE|k}}'''<sup>..Ch</sup>
| rowspan="2"|'''{{PIE|h}}''';<br />'''{{PIE|h/g}}'''<sup>R</sup>
| rowspan="4"|'''{{PIE|g}}''' {{IPA|[ɡ]}};<br />-{{IPA|[ɣ]}}-
| rowspan="2"|'''{{PIE|g}}''';<br />-'''{{PIE|g}}'''- {{IPA|[ɣ]}};<br />-'''{{PIE|g}}''' {{IPA|[x]}}
| rowspan="2"|'''{{PIE|g}}''';<br />-'''{{PIE|y/w}}'''-<sup>(rl)</sup>
| ''*ǵʰans-'' || ''goose'',<br /> [[Old High German|OHG]] ''gans'' || ''haṁsáḥ'' || ''khḗn'' || ''(h)ānser'' || ''žąsìs''
|gh''áz''
|- align=center
!'''{{PIE|*gʰ}}'''
| rowspan="3"|'''{{PIE|gh}}''';<br />'''{{PIE|h}}'''<sup>E</sup> {{IPA|[ɦ]}};<br /> '''{{PIE|g}}'''<sup>..Ch</sup>;<br /> '''{{PIE|j}}'''<sup>E..Ch</sup>
| rowspan="3"|'''{{PIE|g}}''';<br />'''{{PIE|ž}}'''<sup>E</sup> {{IPA|[ʒ]}};<br />'''{{PIE|dz}}'''<sup>E'</sup>
| rowspan="3"|'''{{PIE|g}}'''
|- align=center
!rowspan=2|'''{{PIE|*gʷʰ}}'''
|rowspan=2|'''{{PIE|ph}}''';<br />'''{{PIE|th}}'''<sup>E</sup>;<br />'''{{PIE|kh}}'''<sup>(u)</sup>;<br /> '''{{PIE|p}}'''<sup>..Ch</sup>;<br />'''{{PIE|t}}'''<sup>E..Ch</sup>;<br />'''{{PIE|k}}'''<sup>(u)..Ch</sup>
|rowspan=2|'''{{PIE|f}}'''-;<br />'''{{PIE|g}}''' /<br />-'''{{PIE|u}}'''- {{IPA|[w]}};<br /><sup>n</sup>'''{{PIE|gu}}''' {{IPA|[ɡʷ]}}
|rowspan=2|'''{{PIE|g}}''';<br />'''{{PIE|b}}'''-;<br />-'''{{PIE|w}}'''-;<br /><sup>n</sup>'''{{PIE|gw}}'''
|rowspan=2|'''{{PIE|g}}''';<br />'''{{PIE|b}}'''-;<br />-'''{{PIE|w}}'''-
| ''*sneigʷʰ-'' || ''snow'' || ''sneha-'' || ''nípha'' || ''nivis'' || ''sniẽgas''
|barf
|- align=center
| ''*gʷʰerm-'' || ??''warm'' || ''gharmáḥ'' || ''thermós'' || ''formus'' || [[Latvian language|Latv.]] ''gar̂me''
|garm
|- align=center
! rowspan="2"|'''{{PIE|*s}}'''
| colspan="3"|'''{{PIE|s}}'''
| rowspan="2"|'''{{PIE|h}}'''-;<br />-'''{{PIE|s}}''';<br />'''{{PIE|s}}'''<sup>(T)</sup>;<br />-'''{{PIE|Ø}}'''-;<br />{{IPA|[¯]}}<sup>(R)</sup>
| rowspan="2"|'''{{PIE|s}}''';<br />-'''{{PIE|r}}'''-
| rowspan="2"|'''{{PIE|s}}''' {{IPA|[s]}};<br />-{{IPA|[h]}}-
| rowspan="2"|'''{{PIE|s}}''';<br />`-'''{{PIE|z}}'''-
| rowspan="2"|'''{{PIE|s}}''';<br />`-'''{{PIE|r}}'''-
| ''*septḿ̥'' || ''seven'' || ''saptá'' || ''heptá'' || ''septem'' || ''septynì''
|haft
|- align=center
|'''{{PIE|ṣ}}'''<sup>ruki-</sup> {{IPA|[ʂ]}}
|'''{{PIE|x}}'''<sup>ruki-</sup> {{IPA|[x]}}
|'''{{PIE|š}}'''<sup>ruki-</sup> {{IPA|[ʃ]}}
| ''*h₂eusōs''<br />"dawn" || ''east'' || ''uṣā́ḥ'' || ''āṓs'' || ''aurōra'' || ''aušra''
|b''á''xtar
|- align=center
! '''{{PIE|*m}}'''
| colspan="5"|'''{{PIE|m}}'''
| '''{{PIE|m}}''' {{IPA|[m]}};<br />-{{IPA|[w̃]}}-
| colspan="2"|'''{{PIE|m}}'''
| ''*mūs'' || ''mouse'' || ''mū́ṣ-'' || ''mũs'' || ''mūs'' || [[Old Church Slavonic|OCS]] ''myšĭ''
|mu''š''
|- align=center
! '''{{PIE|*-m}}'''
| -'''{{PIE|m}}'''
| -'''{{PIE|˛}}''' {{IPA|[˜]}}
| colspan="2"| -'''{{PIE|n}}'''
| -'''{{PIE|m}}'''
| -'''{{PIE|n}}'''
| colspan="2"| -'''{{PIE|Ø}}'''
| ''*ḱm̥tóm'' || ''hund(red)'' || ''śatám'' || ''(he)katón'' || ''centum'' || [[Old Prussian|OPrus]] ''simtan''
|sad
|- align=center
! '''{{PIE|*n}}'''
|'''{{PIE|n}}'''
|'''{{PIE|n}}''';<br />-'''{{PIE|˛}}''' {{IPA|[˜]}}
| colspan="6"|'''{{PIE|n}}'''
| ''*nokʷt-'' || ''night'' || ''nákt-'' || ''núkt-'' || ''noct-'' || ''naktis''
|n''áštá''
|- align=center
! '''{{PIE|*l}}'''
|'''{{PIE|r}}''' (dial. '''{{PIE|l}}''')
| colspan="7"|'''{{PIE|l}}'''
| ''*leuk-'' || ''light'' || ''ruc-'' || ''leukós'' || ''lūx'' || ''laũkas''
|ruz
|- align=center
! '''{{PIE|*r}}'''
| colspan="8"|'''{{PIE|r}}'''
| ''*h₁reudʰ-'' || ''red'' || ''rudhirá-'' || ''eruthrós'' || ''ruber'' || ''raũdas''
|sorx
|- align=center
! '''{{PIE|*i̯}}'''
| '''{{PIE|y}}''' {{IPA|[j]}}
| colspan="2"|'''{{PIE|j}}''' {{IPA|[j]}}
|'''{{PIE|z}}''' {{IPA|[dz > zd, z]}} /<br />'''{{PIE|h}}''';<br />-'''{{PIE|Ø}}'''-
|'''{{PIE|i}}''' {{IPA|[j]}};<br />-'''{{PIE|Ø}}'''-
|'''{{PIE|Ø}}'''
|'''{{PIE|j}}'''
|'''{{PIE|y}}'''
|''*yugóm'' || ''yoke'' || ''yugám'' || ''zugón'' || ''iugum'' || ''jùngas''
|yugh
|- align=center
! '''{{PIE|*u̯}}'''
|'''{{PIE|v}}''' {{IPA|[ʋ]}}
|'''{{PIE|v}}'''
|'''{{PIE|v}}''' {{IPA|[ʋ]}}
|'''{{PIE|w > h / Ø}}'''
|'''{{PIE|u}}''' {{IPA|[w > v]}}
|'''{{PIE|f}}''';<br />-'''{{PIE|Ø}}'''-
| colspan="2"|'''{{PIE|w}}'''
|''*h₂weh₁n̥to-'' || ''wind'' || ''vā́taḥ'' || ''áenta'' || ''ventus'' || ''vėtra''
|b''ád''
|-
! PIE !! [[Sanskrit|Skr.]] !! [[Old Church Slavonic|O.C.S.]] !! [[Lithuanian language|Lith.]] !! [[Greek language|Greek]] !! [[Latin]] !! [[Old Irish]] !! [[Gothic language|Gothic]] !! English
|}

:Notes:
* '''C'''- At the beginning of a word.
* -'''C'''- Between vowels.
* -'''C''' At the end of a word.
* `-'''C'''- Following an unstressed vowel ([[Verner's law]]).
* -'''C'''-<sup>(rl)</sup> Between vowels, or between a vowel and '''{{PIE|r, l}}''' (on either side).
* '''C'''<sup>T</sup> Before a (PIE) stop ('''{{PIE|p, t, k}}''').
* '''C'''<sup>T−</sup> After a (PIE) obstruent ('''{{PIE|p, t, k}}''', etc.; '''{{PIE|s}}''').
* '''C'''<sup>(T)</sup> Before or after an obstruent ('''{{PIE|p, t, k}}''', etc.; '''{{PIE|s}}''').
* '''C'''<sup>H</sup> Before an original laryngeal.
* '''C'''<sup>E</sup> Before a (PIE) front vowel ('''{{PIE|i, e}}''').
* '''C'''<sup>E'</sup> Before secondary (post-PIE) front-vowels.
* '''C'''<sup>e</sup> Before '''{{PIE|e}}'''.
* '''C'''<sup>(u)</sup> Before or after a (PIE) '''{{PIE|u}}''' ([[boukólos rule]]).
* '''C'''<sup>(O)</sup> Before or after a (PIE) '''{{PIE|o, u}}''' ([[boukólos rule]]).
* '''C'''<sup>n−</sup> After '''{{PIE|n}}'''.
* '''C'''<sup>R</sup> Before a [[sonorant]] ('''{{PIE|r, l, m, n}}''').
* '''C'''<sup>(R)</sup> Before or after a [[sonorant]] ('''{{PIE|r, l, m, n}}''').
* '''C'''<sup>(r),l,u−</sup> Before '''{{PIE|r, l}}''' or after '''{{PIE|r, u}}'''.
* '''C'''<sup>ruki−</sup> After '''{{PIE|r, u, k, i}}''' ([[Ruki sound law]]).
* '''C'''<sup>..Ch</sup> Before an aspirated consonant in the next syllable ([[Grassmann's law]], also known as [[dissimilation of aspirates]]).
* '''C'''<sup>E..Ch</sup> Before a (PIE) front vowel ('''{{PIE|i, e}}''') as well as before an aspirated consonant in the next syllable ([[Grassmann's law]], also known as [[dissimilation of aspirates]]).
* '''C'''<sup>(u)..Ch</sup> Before or after a (PIE) '''{{PIE|u}}''' as well as before an aspirated consonant in the next syllable ([[Grassmann's law]], also known as [[dissimilation of aspirates]]).