Grimm's law

Grimm's law (also known as the [First] Germanic Sound Shift; German: "Erste Deutsche (Germanische) Lautverschiebung") was the first non-trivial systematic sound change ever to be discovered; its formulation was a turning-point in the development of linguistics, enabling the introduction of rigorous methodology in historical linguistic research. The "law" was discovered by Friedrich von Schegel in 1806 and Rasmus Christian Rask in 1818. These rules were later elaborated on (i.e. extended to include High German) in 1822 by Jakob Grimm, the elder of the Brothers Grimm in his book 'Deutsche Grammatik'. Some scholars use the term Rask's-Grimm's rule. It establishes a set of regular correspondences between early Germanic stops and fricatives (see: Consonant) and the stop consonants of certain other Indo-European languages (Grimm used mostly Latin and Greek for illustration).

As formulated nowadays, Grimm's Law describes the development of inherited Proto-Indo-European (PIE) stops in Proto-Germanic (PGmc, the common ancestor of the Germanic branch of the Indo-European family). It consists of three parts:

  1. Proto-Indo-European voiceless stops change into voiceless fricatives.
  2. Proto-Indo-European voiced stops become voiceless.
  3. Proto-Indo-European voiced aspirated stops lose their aspiration and change into plain voiced stops.

In detail

Further changes following Grimm's Law can sometimes obscure its effects. The most illustrative examples are used here.

Change Germanic examples Non-Germanic (unaffected) examples
*p→f English: foot, Danish: fod, Dutch: voet, German: Fuß, Gothic: fōtus, Icelandic: fótur, Swedish: fot Ancient Greek: πούς (pūs), Latin: pēs, Sanskrit: पाद (pāda)
*t→þ English: third, Old High German: thritto, Gothic: þridja, Icelandic: þriðji Ancient Greek: τρίτος (tritos), Latin: tertius
*k→h English: hound, Danish: hund, Dutch: hond, Faroese: hundur, German: Hund, Gothic: hunds, Icelandic: hundur Ancient Greek: κύων (kýōn), Latin: canis
*kʷ→hw English: what, Gothic: ƕas, Icelandic hvað Latin: quis
*b→p Proto-Indo-European lacked words with *b.
*d→t English: ten, Dutch: tien, Gothic: taíhun, Icelandic: tíu, Norwegian: ti, Swedish: tio Latin: decem
*g→k English: cold, Afrikaans: koud, Danish: kold, Dutch: koud, German: kalt, Icelandic: kaldur, Swedish: kall Latin: gelū
*gʷ→kw English: quick, Gothic: qius, Icelandic: kvikur Latin: vivus "alive"
*bʰ→b English: brother, Danish: broder, Dutch: broeder, German: Bruder, Gothic: broþar, Icelandic: bróðir, Swedish: broder Ancient Greek: φρατηρ (phrātēr), Sanskrit: भ्राता (bhrātā)
*dʰ→d English: door, Danish: dör, Dutch: deur, Frisian: doar, Gothic: daúr, Icelandic: dyr, Norwegian: dör, Swedish: dörr Ancient Greek: θύρα (thýra)
*gʰ→g English: goose, Danish: gås, Dutch: gans, Faroese: gás, Frisian: goes, German: Gans, Icelandic: gæs, Norwegian: gås, Swedish: gås Ancient Greek: χήν (khēn)
*gʷʰ→gw

Exceptions

The voiceless stops did not become fricatives if they were preceded by *s.

Change Germanic examples Non-Germanic examples
*sp English: spew, Gothic: speiwan Latin: spuere
*st English: stand, Dutch: staan, German: stehen, Icelandic: standa, Norwegian: stå Latin: stāre
*sk
*skʷ

*t did not become a fricative if it was preceded by *p, *k, or *kʷ. The stop it was preceded by did fricativize, however.

Change Germanic examples Non-Germanic examples
*pt→ft Gothic: hliftus "thief" Ancient Greek: κλέπτης (kleptēs)
*kt→ht English: eight, Dutch: acht, Frisian: acht, German: acht, Gothic: ahtáu Ancient Greek: οκτώ (oktō), Latin: octō
*kʷt→h(w)t

The most recalcitrant set of apparent exceptions to Grimm's Law, which defied linguists for a few decades, eventually received a brilliant explanation from the Danish linguist Karl Verner (see the article on Verner's law for details).


The Germanic "sound laws", combined with regular changes reconstructed for other Indo-European languages, allow one to define the expected sound correspondences between different branches of the family.

For example, Germanic (word-initial) *b- corresponds regularly to Latin *f-, Greek ph-, Sanskrit bh-, Slavic, Baltic or Celtic b-, etc., while Germanic *f- corresponds to Latin, Greek, Sanskrit, Slavic and Baltic p- and to zero (no initial consonant) in Celtic. The former set goes back to PIE *bh- (faithfully reflected in Sanskrit and modified in various ways elsewhere), and the latter set to PIE *p- (shifted in Germanic, lost in Celtic, preserved in the other groups mentioned here).

Another sound shift in early Germanic which may be early enough to belong in the same general context as Grimm's law is the Germanic spirant law.

Grimm also discovered another ("Second") consonant shift, the High German consonant shift, which accounts for the consonant system of the High Germanic languages.

See also

de:Lautverschiebung eo:Legxo de Grimm fr:loi de Grimm gl:lei de Grimm ja:グリムの法則 ko:그림의 법칙 nl:Eerste Germaanse klankverschuiving pl:Prawo Grimma zh:格里姆定律