Grimms Law

Grimm's Law, the law regulating the interchange of consonants in the Aryan languages (q.v.). Though to some extent anticipated by Rask and others, the discovery was first embodied in a definite law by Jacob Grimm in the 2nd edition of his German Grammar (1822). The rule is that an aspirate in Sanskrit, Greek, Latin, Keltic, Slavonic, and Lithuanian corresponds to a flat mute in the Low German and Scandinavian and a sharp mute in the Old High German and kindred Teutonic dialects; a flat mute in Sanskrit, etc., to a sharp mute in Low German and an aspirate in High German; a sharp mute in Sanskrit, etc., to an aspirate in Low German and a flat mute in High German - as exemplified in the following table: -

The law applies equally to dentals, labials, and gutturals. It does not always hold good, as it may be interfered with by the action of other laws. Dr. Morris in his English Accidence remarks that "no satisfactory explanation has yet been given of this permutation of consonants throughout the Indo-European family of languages."