Here each sound moves one position to the right to take on its new sound value.
The voiced aspirated stops may have first become voiced fricatives before hardening to the voiced unaspirated stops "b", "d", and "g" under certain conditions; however, some linguists dispute this. See Proto-Germanic phonology.
Further changes following Grimm's Law, as well as sound changes in other Indo-European languages, can sometimes obscure its effects. The most illustrative examples are used here.
| Non-Germanic (unshifted) cognates |
Change |
Germanic (shifted) examples |
| Ancient Greek: πούς (poús), Latin: pēs, pedis, Sanskrit: pāda, Russian: под (pod) "under; floor", Lithuanian: pėda, Latvian pēda |
*p→f [ɸ] |
English: foot, West Frisian: foet, German: Fuß, Gothic: fōtus, Icelandic, Faroese: fótur, Danish: fod, Norwegian, Swedish: fot |
| Ancient Greek: τρίτος (tritos), Latin: tertius, Welsh: trydydd, Sanskrit: treta, Russian: третий (tretij), Lithuanian: trečias, Albanian: tretë |
*t→þ [θ] |
English: third, Old Frisian: thredda, Old Saxon: thriddio, Gothic: þridja, Icelandic: þriðji |
| Ancient Greek: κύων (kýōn), Latin: canis, Welsh: ci (pl. cwn) |
*k→h [x] |
English: hound, Dutch: hond, German: Hund, Gothic: hunds, Icelandic, Faroese: hundur, Danish, Norwegian, Swedish: hund |
| Latin: quod, Irish: cad, Sanskrit: kád, Russian: ко- (ko-), Lithuanian: kas |
*kʷ→hw [xʷ] |
English: what, Gothic: ƕa ("hwa"), Icelandic: hvað, Faroese: hvat, Danish: hvad, Norwegian: hva |
| Latin: verber "rod", Homeric Greek: ῥάβδος (rabdos) "rod, wand", Lithuanian: virbas |
*b→p [p] |
English: warp, West Frisian: werpe, Dutch: werpen, Icelandic: verpa, varpa, Faroese: verpa, Gothic wairpan |
| Latin: decem, Greek: δέκα (déka), Irish: deich, Sanskrit: daśan, Russian: десять (desyat'), Lithuanian: dešimt |
*d→t [t] |
English: ten, Dutch: tien, Gothic: taíhun, Icelandic: tíu, Faroese: tíggju, Danish, Norwegian: ti, Swedish: tio |
| Latin: gelū, Greek: γελανδρός (gelandrós), Lithuanian: gelmenis, gelumà |
*g→k [k] |
English: cold, West Frisian: kâld, Dutch: koud, German: kalt, Icelandic, Faroese: kaldur, Danish: kold, Norwegian: kald, Swedish: kall |
| Lithuanian: gyvas |
*gʷ→kw [kʷ] |
English: quick, West Frisian: kwik, kwyk, Dutch: kwiek, Gothic: qius, Icelandic, Faroese: kvikur, Danish: kvik, Swedish: kvick, Norwegian kvikk |
| Sanskrit: bhrātṛ |
*bʰ→b [b]/[β] |
English: brother, West Frisian, Dutch: broeder, German: Bruder, Gothic: broþar, Icelandic, Faroese: bróðir, Danish, Swedish, Norwegian: broder |
| Sanskrit: mádhu 'honey', Homeric Greek: μέθυ methu |
*dʰ→d [d]/[ð] |
English: mead, East Frisian: meede, Dutch: mede, Danish/Norwegian: mjød, Icelandic: mjöður |
| Ancient Greek: χήν (khēn), Sanskrit: hamsa (swan) |
*gʰ→g [ɡ]/[ɣ] |
English: goose, West Frisian: goes, guos, Dutch: gans, German: Gans, Icelandic: gæs, Faroese: gás, Danish, Norwegian, Swedish: gås |
| Homeric Greek: ἐάφθη (eáphthē) "sang, sounded", ὀμφή (omphē) "voice" |
*gʷʰ→gw [ɡʷ]
(After n) |
English: sing, West Frisian: sjonge, Dutch: zingen, German: singen, Gothic: siggwan, Old Icelandic: syngva, syngja, Icelandic, Faroese: syngja, Swedish: sjunga, Danish: synge |
| Sanskrit: gharmá-, Avestan: garəmó, Old Prussian: gorme |
*gʷʰ→gw→w or g
(Otherwise merged with existing g and w) |
English: warm, West Frisian: waarm, Dutch, German: warm, Swedish: varm, Icelandic: varmur |
This is strikingly regular. Each phase involves one single change which applies equally to the labials (p, b, bʰ, f) and their equivalent dentals (t, d, dʰ, þ), velars (k, g, gʰ, h) and rounded velars (kʷ, gʷ, gʷʰ, hʷ). The first phase left the phoneme repertoire of the language without voiceless stops, the second phase filled this gap but created a new one, and so on until the chain had run its course.
There are three main systematic exceptions.
1. The voiceless stops did not become fricatives if they were preceded by *s (itself a fricative).
| Non-Germanic examples |
Change |
Germanic examples |
| Latin: spuere, Lithuanian: spjáuti |
*sp |
English: spew, West Frisian: spije, Dutch: spuwen, German: speien, Danish, Norwegian, Swedish: spy, Icelandic: spýja, Faroese: spýggja, Gothic: speiwan |
| Latin: stāre, Irish: stad, Sanskrit: sta, Russian: стать (stat'), Lithuanian: stoti, Persian: ايستادن (istâdan) |
*st |
English: stand, Icelandic, Faroese, Norwegian: standa, Gothic: standan; West Frisian: stean, Dutch: staan, German: stehen, Danish, Swedish: stå |
| Lithuanian: skurdus |
*sk |
English: short, Old High German: scurz, Icelandic: skorta |
| Irish: scéal |
*skʷ |
English: scold, Icelandic: skáld, Norwegian: skald; West Frisian: skelle, Dutch: schelden, German: schelten |
2. The voiceless stop *t did not become a fricative if preceded by another stop, but the preceding stop was generally devoiced and then fricativised.
Combined with the previous exception it is therefore most convenient to say that in a series of two obstruents, the second does not become a fricative but the first does. This is sometimes treated separately under the heading Germanic spirant law:
| Non-Germanic examples |
Change |
Germanic examples |
| Ancient Greek: κλέπτης (kleptēs), Old Prussian: au-klipts "hidden" |
*pt→ft |
Gothic: hliftus "thief" |
| Latin: atta, Greek: ἄττα (átta) |
*tt→tt |
Old High German: atto, Gothic: atta "father" |
| Ancient Greek: οκτώ (oktō), Irish: ocht, Latin: octō |
*kt→ht |
English: eight, West Frisian, Dutch, German: acht, Gothic: ahtáu, Icelandic: átta (pronounced [ˈauhta]) |
| Irish: anocht, Latin: nox, noct-, Greek: νύξ, νυκτ- (núks, nukt-), Sanskrit: नक्तम् (naktam), Lithuanian: naktis, Hittite (genitive): nekuz (pronounced /nekʷts/) |
*kʷt→ht |
English: night, West Frisian, Dutch, German: nacht, Gothic: nahts, Icelandic: nótt (pronounced [ˈnouht]) |
3. The most recalcitrant set of apparent exceptions to Grimm's Law, which defied linguists for a few decades, eventually received explanation from the Danish linguist Karl Verner (see the article on Verner's law for details). (This is not necessarily an actual exception: the traditional dating of Verner's Law occurring after Grimm's would mean that the consonants affected did undergo Grimm's Law, and were only changed later.)
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, but preserved in the other groups mentioned here).