The Germanic Consonant Shift (also known as the First Sound Shift or Grimm's Law) occurred in five steps. Step 3 is called Verner's Law. Each step was completed before the next began, so there was no over­lapping or repetition of the changes.

The shift is described here in articulatory terms, showing the development of  each sound.

STEP 1: All aspirated voiced stops became the corresponding voiced fricatives:

bh >B              dh >D              gh >Ä               gWh>ÄW

STEP 2: Voiceless stops became the corresponding voiceless fricatives (except when they followed
another voiceless fricative):

p >f                  t >¹                 k >x(h) kW > xW

STEP 3: Voiceless fricatives became voiced (when they were in a voiced environment and the Indo­European stress was not on the preceding syllable):

f>f                    ¹>¹                 x >x                xW >hW            s > s

STEP 4: All voiced stops became unvoiced:

b >p                 d >t                  g >k                 gW >k|qu

STEP 5: Voiced fricatives sometimes became the corresponding voiced stops (the exact conditions depended on the sound, the environment, and the dialect):

B>b                  D > d                Ä> g                 ÄW >gW

In this same step, the voiced fricative z became an r-like sound that was spelled with a distinctive let­ter (transliterated a) in the early runic inscriptions of North Germanic; it later merged with the r inherited from Indo-European.


The IE obstruent system after each step in the Shift. (The labiovelars, kw, gw, gwh, have been omitted for simplicity's sake.)


Step 1
(p t k)* (p t k)*
p t k p t k f¹ x(h) f  ¹  x(h) f  ¹  x(h) f  ¹  x(h)
b d g b d g b d g b d g p t k p t k
bh dh gh B D Ä B D Ä B D Ä B D Ä B D Ä
(B D Ä)*
s s s s s s
r z r

*Sounds in parentheses occurred in limited environments.

In each of the following pairs, the first item is a reconstructed Indo-European root and the second is a related English word. The English word may be based on a form with affixes added to the root or may involve a change in vowel, but the Indo-European consonants  correspond regularly with those in the root of the English word. No exceptions and no examples of Verner's Law (step 3 of the Shift) are involved.  

*bha- 'speak'/    ban *magh- 'can'/ (OE) magan 'may'
*dheu- 'flow'    dew  wegh- 'go'/ (OE) weigh 'way'
*ghans- / goose *plou-  flow
*bend- 'protruding point' pen *aug- 'increase' / eke
*de-/    to *kel- 'cover'     shell
*gel-    cool *leb- / lip
*pan-   few *dem- 'build'    timber
*tr- 'cross over' trough *bhlo- bloom
*kan- 'sing'       hen *dho- 'set, put'   do
*angh- 'tight' anger *turn- 'swollen' thumb
*bher-  bear *tong- 'feel'      tank
*koimo- home, home on the range *pet- 'fly'  feather
*pa- / food *treud- 'squeeze' treat
*swad / sweet *bhreg- / break
*gl- 'ball' clue *bheid- 'split'    bite
*dhren- drone *dhragh­ drag
*Iab- / lap  'lick'  *grebh- 'scratch'  grab
pulo- 'rotten'  foul *porko- / (OE)  fear  ‘small pig'
*wadh- 'pledge'/ wed  *kwerp- 'turn about'/ wharf
*wab- / weep *ghreib-  grip

In the following examples, the Indo-European stress was on some syllable other than the first; consequently Verner's Law (step 3 of the Consonant Shift) applies. 

*kaput (Goth.) haufi¹   'head' *sep(t)m- / (Goth.) sif(¹)un (sibun) 'seven'
*plotu- flood *kluto- / (OE) hlu¹      'loud'
*konk- hank *duka- / (OE) tohian 'tow'
*wes- 'dwell'/ were *sauso- 'dry' / season

The  Indo-European consonants that underwent no change in Germanic:

*lem- 'break'/ (OE) lama 'lame'  (l-m) *newo- 'new'/ (OE) neowe 'new' (n-w)
*ma- 'damp'/ (OE) mo-r 'moor'   (m)  *wel- 'whish' / (OE) wel 'well'  (w-l)
*mel- 'soft' / (OE) mel-tan 'melt' (m-l) *wen- 'strive'/ (OE) winnan 'win' (w-n)
*mer- 'harm'/ (OE) mare 'nightmare' (m-r) *wir- 'man'/ (OE) wer 'man'  (w-r)
*nas- 'nose' / (OE) nosu 'nose' (n-s)  * yero- 'year' / (ModE) year  (y-r)
  ie:nasals, *m, *n; liquids, *l, *r; and semivowels, *w, *j (y).

Grimm’s Law (First Sound Shift)

by John Lawler
Program in Linguistics * University of Michigan
with Kevin McGowan
Copyright © 1993-1997 The Eclectic Company