Semivowels (also called semiconsonants or glides) are vowels that function phonemically as consonants. They are typically briefer, less stable and often closer than the corresponding vowels. For example, the word wow is written in IPA. Even though the first [w] and the last [ʊ] are similar phones, the former is considered a consonant phoneme while the latter is considered a part of the diphthong, because English speakers think wow rhymes with how [haʊ], which means these words share the same syllable rime [aʊ] and the remaining [w] in wow and the [h] in how are both onsets, initial consonants.
Semivowels are classified as approximants that correspond phonetically to specific vowels.
List of semivowels
- English y in yes: the palatal approximant [j]
- English w in well: the labial-velar approximant [w]
- Dutch w except in eeuw: the labiodental approximant [ʋ]
- French hu in huit: the labial-palatal approximant [ɥ]