Topic summary
Vowel breaking

In historical linguistics, vowel breaking, vowel fracture, or diphthongization is the sound change of a monophthong into a diphthong or triphthong: the tongue gliding in one or more directions within the same syllable.
Topic summary

In historical linguistics, vowel breaking, vowel fracture, or diphthongization is the sound change of a monophthong into a diphthong or triphthong: the tongue gliding in one or more directions within the same syllable.