A monophthong ( ) is a pure

vowel A vowel is a speech sound pronounced without any stricture in the vocal tract, forming the nucleus of a syllable. Vowels are one of the two principal classes of speech sounds, the other being the consonant. Vowels vary in quality, in loudness a ...

sound, or one whose articulation at beginning and end is relatively fixed, with the tongue moving neither up nor down and neither forward nor backward towards a new position of articulation. A monophthong can be contrasted with a

diphthong A diphthong ( ), also known as a gliding vowel or a vowel glide, is a combination of two adjacent vowel sounds within the same syllable. Technically, a diphthong is a vowel with two different targets: that is, the tongue (and/or other parts of ...

, where the vowel quality changes (glides from one quality to another) within the same syllable, and with hiatus, where two vowels are next to each other but in different syllables. A vowel sound whose quality does not change over the duration of the vowel is called a pure vowel. The word comes . )

Sound changes

The conversions of monophthongs to diphthongs (diphthongization), and of diphthongs to monophthongs (monophthongization), are major elements of

language change Language change is the process of alteration in the features of a single language, or of languages in general, over time. It is studied in several subfields of linguistics: historical linguistics, sociolinguistics, and evolutionary linguistic ...

and are likely the cause of further changes. In some languages, due to monophthongization,

grapheme In linguistics, a grapheme is the smallest functional unit of a writing system. The word ''grapheme'' is derived from Ancient Greek ('write'), and the suffix ''-eme'' by analogy with ''phoneme'' and other emic units. The study of graphemes ...

s that originally represented diphthongs now represent monophthongs.

References

{{wikt, monophthong Vowels

Sound changes

See also

References