Germanic sound shifts are the phonological developments (sound changes) from the Proto-Indo-European language (PIE) to Proto-Germanic, in Proto-Germanic itself, and in various Germanic subfamilies and languages.
PIE to Proto-Germanic Germanic spirant law Grimm's law Holtzmann's law Sievers' law Verner's law Kluge's law
In Proto-Germanic Germanic a-mutation
Germanic subfamilies and languages Germanic umlaut (all of the early languages except for Gothic) Great Vowel Shift (English) High German consonant shift Ingvaeonic nasal spirant law (attested in Old English, Old Frisian and Old Saxon) West Germanic gemination
See also Germanic languages Germanic substrate hypothesis