Sound Change

Types

Assimilation

The pronunciation of one part of a word changes to become more similar to another part of the word.
[beds] → [bedz] (voiceless → voiced)
[bænk] → [bæŋk] (nasal → nasal+stop)

Dissimilation

Similar consonant or vowel sounds in a word become less similar. Sporadic change, commonly makes words easier to pronounce.
berserk → beøserk (loss)
defibrillator → defibyulator

Metathesis

Re-arranging sounds in a word. Commonly switching adjacent sounds.
foliage → foilage
integral → intergal

Spoonerism

Re-arranging sounds in a words, affecting entire sentences. Special case of Metathesis, Speech Errors.
crushing blow → blushing crow

Weakening

Changing a 'stronger' consonant into a 'weaker' consonant. Voicing, turning into affricate or fricative, loss of place and loss are means of weakening.
write / ride → wriɾe / riɾe (ɾ : 'tap')

Loss

Omission of one or more sounds to make a word easier to pronounce.
fifth → fiøth

Epenthesis

Addition of one or more sounds to make a word easier to pronounce, esp. interior. Opposite of Loss.
drawøing → drawring
(separate vowels)

Prosthesis

Addition of one or more sounds to the beginning of a word to make it easier to pronounce. Special case of Epenthesis.
Lat. østatus → Sp. estado

Umlaut

A process whereby a vowel is pronounced more like a following vowel or semivowel. Distinguishes different forms in a paradigm.
louse / lice

Final Devoicing

A process whereby voiced obstruents (airflow-obstructing consonants) at the end of a word become voiceless.
Ger. Zug 'train' → [tsuk]

Compensatory Lengthening

Lengthening of a vowel sound that happens upon the loss of a following consonant.
Scot. Eng. girl → S. Brit. Eng. gɔl

Palatalization

Dental and velar (typically) consonants move towards palatal articulation.
Lat. *cattus 'cat' → Fr. chat [ša]

Grimm's Law

1. PIE voiceless stops → voiceless fricatives
   

   p → f	'foot'	Rus. pod → Danish fod
   t → ϸ / θ	'three'	Anc. Greek tritos → Goth. thritto
   k → h	'hound'	Anc. Greek kýōn → Dutch hond
   kʷ → hʷ	'what'	Lat. quod → Goth. hwa

2. PIE voiced stops → voiceless stops
   

   b → p	'warp'	Lat. verber → Dutch werpen
   d → t	'ten'	Welsh deg → Faroese tíggju
   g → k	'cold'	Lat. gelū → Faroese kaldur
   gʷ → kʷ	'quick'	Lat. gyvas → Danish kvik

3. PIE voiced aspirates → voiced fricatives (→ voiced stops)
   

   bʰ → b	'brother'	Sanskrit bhrātṛ → Goth. broþar
   dʰ → d	'door'	Sanskrit dwār → Goth. daúr
   gʰ → g	'goose'	Rus. gus' → Frisian guos
   ngʷʰ → ngʷ (→ng)	'tounge'	Arch. Lat. dingua → Goth. tungwō (→Danish tunge)

As a chain shift:

voiced aspirates	3	voiced stops	2	voiceless stops	1	voiceless fricatives
bʰ	→	b	→	p	→	f
dʰ	→	d	→	t	→	ϸ / θ
gʰ	→	g	→	k	→	x (h)
gʷʰ	→	gʷ	→	kʷ	→	xʷ (hʷ)

Verner's Law Voiceless → voiced when

1. immediately following an unstressed syllable.
   

   Sanskrit bhrá̄tā

   OE brōϸor

   'brother'

   Sanskrit pitá̄

   OE fæder

   'father'

2. they are not initial
   

   Sanskrit pitá̄

   OE fæder (not v)

   'father'

3. what precedes & follows is voiced
   

   Lat. stō (s not voiced)

   OE standan (not ð)

   'stand'

As a chain shift:

voiceless fricatives	Grimm	voiceless fricatives	Verner	voiced fricatives (stops)
p	→	f	→	v (b)
t	→	ϸ / θ	→	ð (d)
k	→	x (h)	→	ɣ (g)
kʷ	→	xʷ (hʷ)	→	ɣʷ (gʷ)
s	→	s	→	z

Important Points

• Sound change is limited in time and space.
• Features describe the manner and place of articulation
• Even when sound change is socially motivated (i.e. [šikægo] / [šikago] / [šikɔgo]), it is still phonetically conditioned.