Cowgill's law says that a former vowel becomes between a

resonant Resonance is a phenomenon that occurs when an object or system is subjected to an external force or vibration whose frequency matches a resonant frequency (or resonance frequency) of the system, defined as a frequency that generates a maximu ...

(, , , ) and a

labial consonant Labial consonants are consonants in which one or both lips are the active articulator. The two common labial articulations are bilabials, articulated using both lips, and labiodentals, articulated with the lower lip against the upper teeth, b ...

(including labiovelars), in either order. It is named after Indo-Europeanist

Warren Cowgill Warren Crawford Cowgill ( ; December 19, 1929 – June 20, 1985) was an American linguist. He was a professor of linguistics at Yale University and the Encyclopædia Britannica's authority on Indo-European linguistics. Two separate Indo-Europea ...

. Examples: * 'night' <

PIE A pie is a baked dish which is usually made of a pastry dough casing that contains a filling of various sweet or savoury ingredients. Sweet pies may be filled with fruit (as in an apple pie), nuts ( pecan pie), fruit preserves ( jam tart ...

' (cf. ,

Vedic upright=1.2, The Vedas are ancient Sanskrit texts of Hinduism. Above: A page from the '' Atharvaveda''. The Vedas ( or ; ), sometimes collectively called the Veda, are a large body of religious texts originating in ancient India. Composed ...

< , , gen. sg. ) * 'leaf' <

' (cf. ) * 'mill' <

' (cf. ) * 'nail' (stem ) < early PG ' <

' (cf. < PGerm ') Note that when a labiovelar adjoins an affected by Cowgill's law, the new will cause the labiovelar to lose its labial component (as in and , where the usual Greek change ' > ' has not occurred).

References

*{{cite book, last=Sihler, first=Andrew L., authorlink=Andrew L. Sihler, title=New Comparative Grammar of Greek and Latin, publisher=Oxford University Press, year=1995, isbn=0-19-508345-8 Greek sound laws