Stang's law

Stang's law is a Proto-Indo-European (PIE) phonological rule named after the Norwegian linguist Christian Stang.

The law governs the word-final sequences of a vowel, followed by a semivowel (*y or *w) or a laryngeal (*h₁, *h₂ or *h₃), followed by a nasal. According to the law these sequences are simplified such that laryngeals and semivowels are dropped, with compensatory lengthening of a preceding vowel.

This rule is usually cited in more restricted form as: *Vwm > *Vːm and *Vh₂m > *Vːm (*V denoting a vowel and * a long vowel).