Semivowels

Classification

Semivowels form a subclass of approximants. Although "semivowel" and "approximant" are sometimes treated as synonymous, most authors use the term "semivowel" for a more restricted set; there is no universally agreed-upon definition, and the exact details may vary from author to author. For example, Ladefoged & Maddieson (1996) do not consider the labiodental approximant[ʋ] to be a semivowel (see spirant approximant). Semivowels may be distinguished from the rest of approximants via a feature of prolongability; while all other approximants are prolongable, semivowels are momentary, as prolonging them results instead in the formation of their vocalic equivalents ([j,w] → [i,u]).