monoftonger

Monoftonger are vowel sounds characterized by a single, unchanging quality throughout their duration. The term is used in several languages to denote what English-language phonology calls monophthongs. They contrast with diphthongs, vowels that involve a glide from one quality to another within the same syllable. Many languages have both monophthongs and diphthongs as part of their phonemic inventories, while others rely primarily on monophthongs for their basic vowels.

In articulation and acoustics, a monoftong maintains a stable vocal tract configuration, corresponding to a single vowel height and backness (as well as rounding) for the entire vowel. They can be short or long; in some languages length is phonemic, in others it is not. Vowel quality in a language may be classified as monophthongal or diphthongal, with boundaries between categories sometimes subject to dialectal variation.

Across languages, the prevalence and inventory of monoftonger vary. Spanish and Italian are often described as having five pure vowels, i.e., monophthongs. English features an extensive set of diphthongs; some vowels in certain dialects are treated as long monophthongs in some analyses. In Danish and Norwegian linguistic descriptions, many standard vowels are treated as monoftonger, though dialectal variants can introduce slight dynamic qualities.

See also: diphthong, triphthong, vowel length.