Verner's law by Karl Verner in 1875 describes a historical sound change in the Proto-Germanic language whereby voiceless fricatives *f, *þ, *s, *h, *hʷ following an unstressed syllable became the voiced fricatives *β, *ð, *z, *ɣ, *ɣʷ.
When Grimm's law was discovered, a strange irregularity was spotted in its operation. The Proto-Indo-European (PIE) voiceless stops *p, *t and *k should have – according to Grimm's law – changed into Proto-Germanic (PGmc) *f (bilabial fricative [ɸ]), *þ (dental fricative [θ]) and *h (velar fricative [x]). Indeed, that was known to be the usual development. However, there appeared to be a large set of words in which the agreement of Latin, Greek, Sanskrit, Baltic, Slavic etc. guaranteed PIE *p, *t or *k, and yet the Germanic reflex was voiced (*b, *d or *g).
At first, irregularities did not cause concern for scholars since there were many examples of the regular outcome. Increasingly, however, it became the ambition of linguists like the Neogrammarians to formulate general and exceptionless rules of sound change that would account for all the data (or as close to all the data as possible), not merely for a well-behaved subset of it.
One classic example of PIE *t → PGmc *d is the word for 'father'. PIE *ph₂tḗr (here, the macron marks vowel length) → PGmc *fadēr (instead of expected *faþēr). The structurally similar family term bʰréh₂tēr 'brother' did indeed develop as predicted by Grimm's Law (Gmc. *brōþēr). Even more curiously, they often found both *þ and *d as reflexes of PIE *t in different forms of one and the same root, e.g.*werþaną 'to turn', preterite third-person singular *warþ 'he turned', but preterite third-person plural *wurdun and past participle *wurdanaz.
Karl Verner is cred as the first scholar to note the factor governing the distribution of the two outcomes. He observed that the apparently unexpected voicing of voiceless stops occurred if they were non-word-initial and if the vowel preceding them carried no stress in PIE. The original location of stress was often retained in Greek and early Sanskrit; in Germanic, though, stress eventually became fixed on the initial (root) syllable of all words. The crucial difference between *patḗr and *bʰrā́tēr was therefore one of second-syllable versus first-syllable stress (compare Sanskrit pitā́ versus bhrā́tā).
The *werþaną : *wurdun contrast is likewise explained as due to stress on the root versus stress on the inflectional suffix (leaving the first syllable unstressed). There are also other Vernerian alternations, as illustrated by modern German ziehen 'to draw, pull' : Old High zogōn 'to tug, drag' ← PGmc. *teuhaną : *tugōną ← Pre-Germanic *déwk-o-nom : *duk-éh₂-yo-nom 'lead'.
There is a spinoff from Verner's Law: the rule accounts also for PGmc *z as the development of PIE *s in some words. Since this *z changed to *r in the Scandinavian languages and in West Germanic (German, Dutch, English, Frisian), Verner's Law resulted in alternation of *s and *r in some inflectional paradigms, known as grammatischer Wechsel. For example, the Old English verb ceosan 'choose' had the past plural form curon and the past participle (ge)coren. These three forms derived from Proto-Germanic *keusaną : *kuzun ~ *kuzanaz, which again derived from Pre-Germanic *géws-o-nom : *gus-únt ~ *gus-o-nós 'taste, try'. We would have **chorn for chosen in Modern English if the consonantal shell of choose and chose had not been morphologically levelled (compare the Dutch kiezen 'to choose' : verkoren 'chosen'). On the other hand, Vernerian *r has not been levelled out in En were ← PGmc *wēzun, related to En was. Similarly, En lose, though it has the weak form lost, also has the archaic form †lorn (now seen in the compound forlorn) (compare Dutch verliezen : verloren); in German, on the other hand, the *s has been levelled out both in war 'was' (plural waren 'were') and verlieren 'lose' (participle verloren 'lost').
The following table illustrates the sound changes according to Verner. In the bottom row, for each pair, the sound on the right represents the sound changed according to Verner's Law.
Karl Verner published his discovery in the article "Eine Ausnahme der ersten Lautverschiebung" (an exception to the first sound shift) in Kuhn's Journal of Comparative Linguistic Research in 1876, but he had already presented his theory on 1 May 1875 in a comprehensive personal letter to his friend and mentor, Vilhelm Thomsen.
It was received with great enthusiasm by the young generation of comparative philologists, the so-called Junggrammatiker, because it was an important argument in favour of the Neogrammarian dogma that the sound laws were without exceptions ("die Ausnahmslosigkeit der Lautgesetze").
It is worth noting that the change in the pronunciation of the consonant, described by Verner's Law, must have occurred before the shift of stress to the first syllable. The voicing of the new consonant in Proto-Germanic is conditioned by which syllable is stressed in Proto-Indo-European, yet this syllabic stress has disappeared in Proto-Germanic, so the change in the consonant must have occurred at a time when the syllabic stress in earlier Proto-Germanic still conformed to the Indo-European pattern. However, the syllabic stress shift erased the conditioning environment, and made the variation between voiceless fricatives and their voiced alternants look mysteriously haphazard.
Until recently it was assumed that Verner's law was productive after Grimm's Law. Now it has been pointed out (Vennemann 1984:21, Kortlandt 1988:5–6) that, even if the sequence is reversed, the result can be just the same given certain conditions. Noske (2012) argues that Grimm's Law and Verner's Law must have been part of a single bifurcating chain shift.
Some scholars today—e.g. Wolfram Euler and Konrad Badenheuer (2009), pp. 54 f. and 61–64, see below—are inclined towards preferring a new theory in which the sequence of the two changes is the opposite of what was previously assumed. This chronological reordering, however, has far-reaching implications on the shape and development of the Proto-Germanic language. The traditionally assumed order has been gradually put into question since around 1998, based on the following two main arguments:
Moreover, the combination of the above-mentioned traditional order (Grimm's before Verner's) and the dating of Grimm's law to the 1st century BC requires an unusually fast change of the late Common Germanic at the turn of the millennium: within only a few decades, the three dramatic changes mentioned below would have had to happen in quick succession. This would be the only way to explain that all Germanic languages show these changes. Such a rapid language change seems implausible.
Against this background, the thesis that Verner's Law might have been valid before Grimm's Law—maybe long before it—has been finding more and more acceptance. Accordingly this order now would have to be assumed:
If Kluge's law is valid, it also requires Verner's law to precede Grimm's.
Here is a table with an alternative view of Verner's law, occurring before the shift of Grimm's law.
It is required to postulate aspiration in the voiceless stops, because the results of Verner's law merge with the descendants of the voiced aspirate stops, not of the plain voiced stops. (This can however be bypassed in the glottalic theory framework, where the voiced aspirate stops are replaced with plain voiced stops, and plain voiced stops with glottalized stops.)
There is, however, a phonologic argument against this dating: The traditional order makes it possible to narrow down the effect of Verner's law to the voiceless fricatives. If on the other hand one wants to apply the First Sound Shift after Verner's law, one has to suppose that Verner's law applies both to voiceless plosives *p, *t, *k and *kʷ and to the voiceless fricative *s. In other words, in this scenario, Verner's law affected all obstruents, not just fricatives. As for the names Cimbri and Vacalus, it could simply be that the presence of /k/ in these two words was due to Roman scribes hearing the early Germanic *h (/x/) sound as a /k/ rather than an /h/, since their own /h/ did not often occur between vowels and was at any rate already in the process of going silent.
An exact parallel to Verner's law is found in the neighboring Finnic languages, where it forms a part of the system of consonant gradation: a single voiceless consonant (*p, *t, *k, *s) becomes weakened (*b, *d, *g; *h < *z) when occurring after an unstressed syllable. As word stress in Finnic is predictable (primary stress on the initial syllable, secondary stress on odd-numbered non-final syllables), and has remained so since Proto-Uralic, this change did not produce any alternation in the shape of word roots. However, it manifests in the shape of numerous inflectional or derivational suffixes, and is therefore called "suffixal gradation".
|'tree' (nom. : part.)||*puu : *ˈpuu-ta||*puu : *puuta||puu : puuta|
|'hut, teepee' (nom. : part.)||*ˈkota : *ˈkota-ta||*ˈkota : *ˈkotada||kota : kotaa|
|'dead, corpse' (nom. : part.)||*ˈsoketa : *ˈsokeˌta-ta||*ˈsokeda : *ˈsokeˌdata||sokea : sokeata|
Lauri Posti (1953: 74–82) argued that suffixal gradation in Finnic represents Germanic influence, in particular reflecting the pronunciation of Proto-Finnic by a hypothetical Germanic-speaking superstrate (often assumed to account for the great number of Germanic loanwords already in Proto-Finnic). On the contrary, consonant gradation has also been viewed as inheritance from Proto-Uralic, as it occurs also in other Uralic languages. In particular, suffixal gradation under identical conditions also exists in Nganasan. The possibility of the opposite direction of influence – from Finnic to Germanic – has also been suggested as possible.