Cowgill's law in Greek
- núks "night" < PIE *nokʷts (cf. Lat. nox, Ved. nák < *nakts, Goth. nahts, Hitt. gen. sg. nekuz /nekʷts/)
- phúllon "leaf" < PIE *bholyom (cf. Lat. folium)
- múlē "mill" < PIE *mol-eh₂- (cf. Lat. molīna)
- ónuks "nail" (stem ónukh-) < early PG *onokʷh- < PIE h₃nogʷh- (cf. OE nægl < PGerm *nag-laz)
Note that when a labiovelar adjoins an /o/ affected by Cowgill's law, the new /u/ will cause the labiovelar to lose its labial component (as in núks and ónuks/ónukh-).
Cowgill's law in Germanic
Cowgill's law in Germanic has no relation to Cowgill's law in Greek other than having been named after the same person. It says that a PIE laryngeal /h₃/, and possibly /h₂/, turns into /k/ in Proto-Germanic when directly preceded by a sonorant and followed by /w/. This law is still controversial, although increasingly accepted. Donald Ringe (2006) accepts it; Andrew Sihler (1995) is noncommittal.
Examples are fairly few:
- *kwikwaz "alive" (whence English quick) < PIE *gʷih₃-wos (cf. Lat. vīvus)
- *unkw- "us two" (cf. Goth. unkis) < PIE *n̥h₃we (cf. Gk. nṓ; Ved. āvā́m acc. du. "us two" < *āva-ám)
- Possibly OE tācor "husband's brother" < PIE *dayh₂wer
If it becomes generally accepted, the relative chronology of this law could have consequences for a possible reconstructed phonetic value of h₃. Since Germanic /k/ results from earlier PIE /g/, and since the change occurred before Grimm's law applied (according to Ringe), the resulting change would be actually h₃w > gʷ. This would have been more likely if h₃ was a voiced velar obstruent to begin with. If h₃ was a voiced labiovelar fricative as is occasionally suggested, the change would therefore have been: ɣʷw > ɡʷ.