Diphthong

A diphthong is a vowel whose quality changes significantly in one direction during its pronunciation.

• "When the medial phase shows an audible change of quality, with the change consistently progressing toward a single target, as it were, then the sound is classified as a diphthong." (Laver 1994:146)

Examples

[ai] in English wine, [au] in English house.

Comments

Often phonologists do not agreee whether a tautosyllabic sequence of two sounds is a diphthong or a sequence of vowel plus glide, or glide plus vowel.

Subtypes

• falling diphthong
• rising diphthong

Origin

From Greek di-phthongos [two-sound]. The word is first attested in English in the 15th century.

Related terms

• monophthong (a vowel whose quality does not change)
• triphthong (a vowel whose quality changes twice during its pronunciation)
• diphthongization

References

• Laver, John. 1994. Principles of phonetics. Cambridge: Cambridge University Press.

Other languages

German Diphthong (de) Czech dvouhláska