Indo-European sound laws

As the Proto-Indo-European language (PIE) broke up, its sound system diverged as well, according to various sound laws in the daughter languages.

Especially notable is the palatalization that produced the Satem languages, along with the associated ruki sound law. Other notable changes are Grimm's law and Verner's law in Proto-Germanic; an independent change similar to Grimm's law in Armenian; loss of prevocalic *p- in Proto-Celtic; Brugmann's law in Proto-Indo-Iranian; Winter's law and Hirt's law in Balto-Slavic; and merging of voiced and breathy-voiced stops, and /a/ and /o/, in various "northern" languages. Bartholomae's law in Indo-Iranian, and Sievers' law in Proto-Germanic and (to some extent) various other branches, may or may not have been a common Indo-European feature. A number of innovations, both phonological and morphological, represent areal features common to the Italic and Celtic languages; among them are the development of labiovelars to labial consonants in some Italic and Celtic branches, producing "p-Celtic" and "q-Celtic" languages (likewise "p-Italic" and "q-Italic", although these terms are less used). Another grouping with many shared areal innovations is Greek, Indo-Iranian, and Armenian; among the common phonological innovations are Grassmann's law in Greek and Indo-Iranian, and weakening of pre-vocalic /s/ to /h/ in Greek, Iranian and Armenian.

Note - these draft tables need to be completed, verified, and the allophones explained.

1 Consonants
2 Vowels and syllabic consonants
3 Examples
- 3.1 *p
- 3.2 *t
- 3.3 *ḱ
- 3.4 *k
4 Sound laws within PIE
5 References
6 Bibliography
7 See also

Consonants

**Proto-Indo-European consonants and their reflexes in selected Indo-European daughter languages**
PIE	Skr.	Av.	O.C.S.	Lith.	Alb.	Arm.	Hitt.	Toch.	Greek	Greek+[j]	Latin	Old Irish	Gothic	English
*p	p; ph¹⁶	p; f¹⁷	p			h; w¹	p			pt	p	Ø; ch [x]²	f; b [β]³	f; v, f⁸
*sp	normal development of /s/+/p/				f	normal development of /s/+/p/						f	sp
*t	t; th¹⁶	t; θ¹⁷	t			tʿ [tʰ]	t; z [ts]⁵	t; c [c]⁵	t	s; tt/ss¹	t	t; th [θ]⁸	þ [θ]; d [ð];³ t⁴	th; d;³ t⁴
*t+t [tst]	tt; tth¹⁶	st; sθ¹⁷?	st		s	s?	zt [tst]	ss?	st		ss		ss or st
*st	normal development of /s/+/t/				sht [ʃt]	normal development of /s/+/t/					st
*ḱ	ś [ɕ]	s		š [ʃ]	th [θ]; k⁹	s	k	k; ś [ɕ]⁹	k		c [k]	c [k]; ch [x]⁸	h; g [ɣ]³	h; Ø;⁸ y³
*k	k; c [tʃ];⁵ kh¹⁶	k; c [tʃ];⁵ x¹⁷	k; č [tʃ];⁵ c [ts]¹⁰	k	k	kʿ [kʰ]	k		k		c [k]		h; g [ɣ]³	h; Ø;⁸ y³
*kʷ	k; c [tʃ];⁵ kh¹⁶	k; c [tʃ];⁵ x¹⁷	k; č [tʃ];⁵ c [ts]¹⁰	k	k; s;⁵ q [c]¹⁰	kʿ [kʰ]	ku		p; t;⁵ k⁶		qu [kʷ]; c [k]⁷		ƕ [ʍ]; gw, w³	wh; w³
*sḱ	ćh; ććh¹	s?	s?	š?	h	?? č`; c`¹	normal dev. of /s/+/ḱ/		sk; kh;¹⁹ skh²⁰		sc [sk]		sk	sh [ʃ]
*sk	normal development of /s/+/k/				?	normal development of /s/+/k/			sk; kh;¹⁹ skh²⁰		sc [sk]		sk
*skʷ	normal development of /s/+/kʷ/				?	normal development of /s/+/kʷ/					squ [skʷ]	sc [sk]	sq
*b	b; bh¹⁶	b; β¹⁸	b			p			b	pt	b	b [b]; [β]⁸	p
*d	d; dh¹⁶	d; δ¹⁸	d		d; dh [ð]⁸	t		ts; ś [ɕ]⁵	d	z [zd > dz > z]	d	d [d]; [ð]⁸	t
*ǵ	j [dʒ]; h [ɦ]¹⁶	z		ž [ʒ]	dh [ð]; g⁹	c [ts]	k	k; ś [ɕ]⁹	g		g	g [ɡ]; [ɣ]⁸	k	c / k; ch¹⁰
*g	g; j [dʒ];⁵ gh;¹⁶ h [ɦ]^16,5	g; j [dʒ];⁵ γ¹⁸	g; ž [ʒ];⁵ dz¹⁰	g	g	k	k		g		g	g [ɡ]; [ɣ]⁸	k	c / k; ch¹⁰
*gʷ	g; j [dʒ];⁵ gh;¹⁶ h [ɦ]^16,5	g; j [dʒ];⁵ γ¹⁸	g; ž [ʒ];⁵ dz¹⁰	g	g; z;⁵ gj [ɟ]¹⁰	k	ku		b; d;⁵ g⁶		u [w > v]; gu [ɡʷ]¹⁵	b [b]; [β]⁸	q [kʷ]	qu
*bʰ	bh [bʱ]	b; β¹⁸	b			b; w⁸	p		ph [pʰ]	pt	f;²¹ b	b [b]; [β]⁸	b [b]; b [β];⁸ f¹³	b; v / f²⁴
*dʰ	dh [dʱ]	d; δ¹⁸	d				t	t; c [c]⁵	th [tʰ]	tt/ss	f;²¹ d; b¹⁴	d [d]; [ð]⁸	d; d [ð];⁸ þ¹³	d
*ǵʰ	h [ɦ]	z		ž [ʒ]	dh [ð]; d⁹	j [dz]; z⁸	k	k; ś [ɕ]⁵	ch [kʰ]		h; h / g⁹	g [ɡ]; [ɣ]⁸	g; g [ɣ];⁸ g [x]¹³	g; y / w²⁴
*gʰ	gh [ɡʱ]; h [ɦ]⁵	g; j [dʒ];⁵ γ¹⁸	g; ž [ʒ];⁵ dz¹⁰	g	g	g; ǰ [dʒ]⁵	k		ch [kʰ]		h; h / g⁹		g; g [ɣ];⁸ g [x]¹³	g; y / w²⁴
*gʷʰ	gh [ɡʱ]; h [ɦ]⁵	g; j [dʒ];⁵ γ¹⁸	g; ž [ʒ];⁵ dz¹⁰	g	g; z;⁵ gj [ɟ]¹⁰	g; ǰ [dʒ]⁵	ku		ph [pʰ]; th [tʰ];⁵ ch [kʰ]⁶		f;²¹ g / u [w];⁸ gu [ɡʷ]¹⁵		g; b;²¹ w;⁸ gw¹⁵	g; b;²¹ w;⁸
*s	s	h [h, x]; s²	s		sh [ʃ]; gj [ɟ];¹² h⁸	h; s;² Ø⁸	š [s]	s; ṣ [ʂ]	h;²¹ s;^{22, 13} Ø;⁸ [¯]²³	i	s; r⁸	s [s]; [h]⁸	s; z³	s; r³
*s	ṣ [ʂ]¹¹	š [ʃ]¹¹	x [x]¹¹	š [ʃ]¹¹	sh [ʃ]; gj [ɟ];¹² h⁸	h; s;² Ø⁸	š [s]	s; ṣ [ʂ]	h;²¹ s;^{22, 13} Ø;⁸ [¯]²³	i	s; r⁸	s [s]; [h]⁸	s; z³	s; r³
*m	m									in	m	m [m]; [w̃]⁸	m
*-m¹³	m		˛ [˜]	n		Ø		n		--	m	n	Ø
*n	n		n; ˛ [˜]¹³	n				n; ñ [ɲ]	n	in	n
*l	r (dial. l)	r	l		l; ll [ɫ]⁸	l / ɫ [ɫ > ɣ]	l			il	l
*r	r				r [ɾ]; rr [r]⁸	r				ir	r
*i̯	y [j]		j [j]		gj [ɟ]; Ø	Ø	y [j]		z [zd > dz > z] / h; Ø ⁸	?i	i [j]; Ø ⁸	Ø	j	y
*u̯	v [ʋ]	v [w]	v	v [ʋ]	v	g / w	w		w > h / Ø	i	u [w > v]	f; Ø⁸	w
PIE	Skr.	Av.	O.C.S.	Lith.	Alb.	Arm.	Hitt.	Toch.	Greek	Greek+/y/	Latin	Old Irish	Gothic	English

Notes:

¹ After a vowel.
² Before a plosive (p, t, k).
³ Following an unstressed vowel (Verner's law).
⁴ After a (PIE) stop or s.
⁵ Before a (PIE) front vowel (i, e).
⁶ Before or after a (PIE) u.
⁷ Before or after a (PIE) o, u.
⁸ Between vowels.
⁹ Before a sonorant.
¹⁰ Before secondary (post-PIE) front-vowels.
¹¹ After r, u, k, i (Ruki sound law).
¹² Before a stressed vowel.
¹³ At the end of a word.
¹⁴ After u, r or before r, l.
¹⁵ After n.
¹⁶ Before an original laryngeal.
¹⁷ Before a consonant or original laryngeal.
¹⁸ In Younger Avestan, after a vowel.
¹⁹ After r, l, m, n, t, d, possibly other consonants?
²⁰ After (Greek) th.
²¹ At the beginning of a word.
²² Before or after an obstruent (p, t, k, etc.; s).
²³ Before or after a resonant (r, l, m, n).
²⁴ Between vowels, or between a vowel and r, l (on either side).

Vowels and syllabic consonants

**Proto-Indo-European vowels and syllabic consonants, and their reflexes in the Indo-European daughter languages**
Trad. PIE	Laryng. PIE	Skr.	Av.	O.C.S.	Lith.	Arm.	Alb.	Toch.	Hitt.	Greek	Latin¹⁸	Proto-Celtic	Gothic¹⁹
*e	e, h₁e	a		e			je, ie, e, i; ja¹²	ä	e, i	e			i; ai [ɛ]²
*a	(a³), h₂e			o	a	a	ha, a	ā	ha, a	a			a
*o	*h₃e					o, a	a	a, e	a	o
*o	*o	a; ā⁴				o, a		a, e	a	o
*ə¹⁶	*h₁¹⁶	i	i, Ø	Ø		a, Ø		ā	a	e	a		a, Ø
	*h₂¹⁶								h	a
	*h₃¹⁶									o
*-	*h₁-¹⁷	Ø				e (a?)	Ø		a	e (o)	Ø
	*h₂-¹⁷					a			ha	a
	*h₃-¹⁷					a			a, ha	o
*ē	ē, eh₁	ā		ě	ė	i	o, ua	a/e?; ā?⁸	e, i	ē		ī	ē
*ā	(ā³), eh₂			a	o [oː]	a	o, ua	a/o?	a, ah	ā > ē¹⁵	ā	ā	ō
*ō	ō, eh₃			a	uo	u	e	a/ā?; ū?⁸	a	ō		ā; ū⁸	ō
*i	*i	i		ь	i	i	i; e¹⁰	ä	i	i			i; ai [ɛ]²
*ī	*ih₁	ī		i	y [iː]	i	i	i		ī	ī		ei [iː]
	*ih₂					i or ^(j)a?⁷		yā		ī or ^(j)ā?⁷
	*ih₃					i or ^(j)a?⁷		yā		ī or ^(j)ō?⁷
*ei	ei, h₁ei	ai > ē	ai > ōi, āi > aē⁴		ei; ie⁵	i		e	ei	ei	ī	īa; ē⁶
*oi	oi, h₃ei			ě	ai; ie⁵	e	e, ai		ay	oi	ū	oe	ai
*ai	(ai³), h₂ei			ě	ai; ie⁵	e	e, ai		ay	ai	ae	ae	ai
*ēi	*ēi	āi; ā⁸	āi; ā(i)⁸	i			i			ēi	ī?		ei [iː]
*ōi	ōi (oei)			y; u⁸	ai; ui⁸		e, ai		ai	ōi	ō	^u⁸	ai
*āi	*eh₂ei			ě			e, ai			āi > ēi¹⁵	ae		ai
*u	*u	u		ъ	u	u	u; y¹¹	ä	u	u	u	u; o¹	u; au [ɔ]²
*ū	*uh₁	ū		y	ū	u	y; i⁸	u		ū	ū
	*uh₂					u or ^(w)a?⁷		wā		ū or ^(w)ā?⁷
	*uh₃					u or ^(w)a?⁷		wā		ū or ^(w)ō?⁷
*eu	eu, h₁eu	ō	ə̄u; ao⁴	ju	iau	oy	e	u		eu	ū	ūa; ō⁹	iu
*ou	ou,h₃eu			u	au	oy	a	o, au		ou	ū		au
*au	(au³), h₂eu			u	au	aw	a	o, au		au	au		au
*ēu	*ēu	āu		u	iau		e				ū?		au
*ōu	*ōu	āu					a			ō
*m̥	*m̥	a		ę	im̃; um̃¹⁴	am	a	äm	am	a	em	em, am	um
*m̥̅	*mh₁	ā			ìm; ùm¹⁴	ama		mā		mē	mā
	*mh₂									mā > mē¹⁵
	*mh₃									mō
*m̥m	*m̥m	am		ьm/ъm	im; um¹⁴	am				am	em	am
*n̥	*n̥	a		ę	iñ; uñ¹⁴	an		än	an	a	en	en, an	un
*n̥̄	*nh₁	ā			ìn; ùn¹⁴	ana		nā		nē	nā
	*nh₂									nā > nē ¹⁵
	*nh₃									nō
*n̥n	*n̥n	an		ьn/ъn	iñ; uñ¹⁴	an				an	en	an
*l̥	*l̥	ṛ	ərə	lь/lъ	il̃; ul̃¹⁴	al	il, li; ul, lu	äl	al	la	ol	li	ul
*l̥̄	*lh₁	īr; ūr¹³	arə		ìl; ùl¹⁴	ala	al	lā		lē	lā
	*lh₂									lā > lē¹⁵
	*lh₃									lō
*l̥l	*l̥l	ir; ur¹³	ar	ьl/ъl	il; ul¹⁴	al, la				al	el	al
*r̥	*r̥	ṛ	ərə	rь/rъ	ir̃; ur̃¹⁴	ar	ir, ri; ur, ru	är	ar	ra	or	ri	aur
*r̥̄	*rh₁	īr; ūr¹³	arə		ìr; ùr¹⁴	ara	ra	rā		rē	rā
	*rh₂									rā > rē¹⁵
	*rh₃									rō
*r̥r	*r̥r	ir; ur¹³	ar	ьr/ъr	ir; ur¹⁴	ar				ar	ar	ar
Trad. PIE	Laryng. PIE	Skr.	Av.	O.C.S.	Lith.	Arm.	Alb.	Toch.	Hitt.	Greek	Latin¹⁸	Proto-Celtic	Gothic¹⁹

Notes

¹ Before wa.
² Before r, h. Gothic, but not other Germanic languages, merges /e/ and /i/.
³ The existence of PIE non-allophonic a is disputed.
⁴ In open syllables (Brugmann's law).
⁵ Under stress.
⁶ Before palatal consonants.
⁷ The so-called breaking is disputed (typical examples are *proti-h₃kʷo- > Ved. prátīkam ~ Gk. πρόσωπον; *gʷih₃u̯o- > Ved. jīvá- ~ Arm. keank‘, Gk. ζωός; *duh₂ro- > Ved. dūrá- ~ Arm. erkar, Gk. δηρός)
⁸ In a final syllable.
⁹ Before velars and unstressed
¹⁰ Before ā in the following syllable.
¹¹ Before i in the following syllable.
¹² In a closed syllable.
¹³ In the neighbourhood of labials.
¹⁴ In the neighbourhood of labiovelars.
¹⁵ ā > ē in Attic and Ionic dialects only.
¹⁶ Between consonants, or at the end of a word after a consonant.
¹⁷ At the beginning of a word, followed by a consonant.
¹⁸ In initial syllables only.
¹⁹ In non-final syllables only.

Examples

See the list of Proto-Indo-European roots hosted at Wiktionary.

*p

*pṓds, ~ *ped-, "foot".^[1]

Vedic Sanskrit: pád-
Avestan: pâdha
Slovenian: pòd, "floor"
Lithuanian: pėda, "foot bottom"
Armenian: otn
Tocharian: A pe, B pai
Luwian: pa-da-, pa-ta-
Greek: poús, podós
Latin: pēs, pedis
Scottish Gaelic: edh, "pace"
Gothic: fotus (*p -> f by Grimm's Law)

*t

*tréyes, "three".^[2]

Vedic Sanskrit: tráyas
OCS: trьje
Lithuanian: trỹs
Albanian: tre
Greek: treĩs
Latin: trēs
Irish: tri
Old Norse: þrir (*t -> þ by Grimm's Law)

*ḱ

*ḱm̥tóm, "hundred" (from earlier *dk̂m̥tóm)^[3]

Vedic Sanskrit: śatám
Later Avestan: satəm
OCS: sьto
Lithuanian: šimtas
Tocharian: A känt, B känte
Greek: hekatón
Latin: centum (i.e., kentum)
Welsh: cant
Gothic: hund- (from proto-Germanic *xund)^[4]

*k

*kreuh₂, "raw flesh" ^[5]

Vedic Sanskrit: kravíṣ-, "raw meat"
Lithuanian: kraûjas, "blood"
OCS: krьvь, "blood"
Greek: kréas, "meat"
Latin: cruor, "raw blood"
Irish: cró, "blood, gore"
Old English: hrō, "raw"

Sound laws within PIE

A few phonological laws can be reconstructed that may have been effective prior to the final breakup of PIE by internal reconstruction.

Sievers' law (Edgerton's law, Lindeman's option)
Bartholomae's law
Szemerényi's law
Stang's law
Siebs' law

References

^ Meier-Brügger (2003), p. 128
^ Meier-Brügger (2003), p. 127
^ Meier-Brügger (2003), pp. 101-102
^ Hock, Hans Heinrich (1986). Principles of historical linguistics. Berlin; New York: Walter de Gruyter. p. 132. ISBN 3110106000. http://books.google.com/books?id=bZi64Oi8mDMC.
^ Meier-Brügger (2003), p. 131

Bibliography

Meier-Brügger, Michael; Matthias Fritz, Manfred Mayrhofer, Charles Gertmenian (trans.) (2003). Indo-European Linguistics. Berlin; New York: Walter de Gruyter. ISBN 3110174332. http://books.google.com/books?id=49xq3UlKWckC.