A monophthong (Greek monóphthongos from mónos "single" and phthóngos "sound") is a pure vowel sound, one whose articulation at both beginning and end is relatively fixed, and which does not glide up or down towards a new position of articulation.
The opposite is a diphthong, where the vowel quality changes within the same syllable, and hiatus, where two vowels are next to each other in different syllables.
Sound changes
The conversion of monophthongs to diphthongs (
diphthongization) or of diphthongs to monophthongs (
monophthongization), is a major element of
language change and is likely the cause of further changes.
English
Some sounds that may be perceived by native speakers as monophthongs in English are, in fact, diphthongs; the vowel sound in
pay — pronounced is an example of this.
Some dialects of English make monophthongs out of former diphthongs. Also, the speech of the southern United States tends to alter the diphthong as in eye to an somewhere between and .
On the other hand, former monophthongs have become diphthongs in American English such as the in words like pin changing to in some American dialects.
Sanskrit
Historically, some languages treat vowel sounds that were formerly diphthongs as monophthongs. Such is the case in
Sanskrit, in whose grammar the sounds now realised as and are conceptually
ai and
au, and are written that way in the
Devanagari and related alphabets. The sounds and exist in Sanskrit, but are written as if they were
āi and
āu, with long initial vowels.
Similar processes of the creation of new monophthongs from old diphthongs are preserved in the traditional spellings of languages as diverse as French and Modern Greek.
See also
Diphthong
Hiatus
Index of phonetics articles
List of vowels
List of phonetics topics
Semivowel
Triphthong
Vowel
Vowel cluster
Vowel breaking
References
Category:Vowels
