Cowgill's law (Germanic)

Cowgill's Law is a proposed sound law in Proto-Germanic historical linguistics which seeks to explain certain exceptions to Verner's Law. Verner's Law, a major sound change in Proto-Germanic, stated that voiceless fricatives (derived from Proto-Indo-European voiceless stops) became voiced when the preceding syllable was unstressed in Proto-Indo-European.

Cowgill's Law, named after Warren Cowgill, suggests that in some cases where Verner's Law would be expected to apply, the voiceless fricative remained voiceless. The law proposes that this happened when the following syllable was accented in Proto-Indo-European, effectively "canceling" or overriding the conditions for Verner's Law.

The precise formulation and validity of Cowgill's Law remain a subject of debate among historical linguists specializing in Germanic. Some researchers have offered alternative explanations for the same phenomena, arguing that other factors, such as analogy or dialectal variation, were responsible for the apparent exceptions to Verner's Law. While the law is useful in explaining some recalcitrant forms, its acceptance is not universal within the field.