Verner's Law
Definition - A law formulated by Karl Verner in 1875 that solved a discrepency in Grimm's law. It explains the sound-change evolution in Proto-Germanic that happened to the voiceless fricatives *f, *þ, *s, *h (including *hʷ ) in the situation where they immediately followed an unstressed syllable in the same word. When this occurred, they were voiced and over time became, respectively, *b, *d, *z, *g (and *gʷ).

The story of Verner's Law - Part 1

Part 2

Part 3

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