to diphthongize

1 9.9

To change a single vowel sound into two vowel sounds

verb
/ˈdɪfθɔŋˌaɪz/

Specialized

: diptongar

But this apparent irregularity, in fact, reinforces the link to domare since the stem-vowel of Sp. domar similarly failed to diphthongize under stress.

Examples

Latin tonic /o/, i.e., close o, should not have diphthongized, but apparently did.

Academic text (1993)
When the vowel sound is stressed, it tends to diphthongize, transforming into a glide.
Some languages naturally diphthongize certain vowel sounds, changing their pronunciation.
In English, the vowel in 'ride' diphthongizes, resulting in a more complex sound.

Surface Forms

diphthongize infinitive

diphthongized past

diphthongized past participle

diphthongizing present participle

diphthongizes third person singular

Morphology

diphthongize = diphthong (transparent) = diphthong + ize

Formed by the noun 'diphthong' plus the productive verb-forming suffix '-ize', meaning 'to make or pronounce as a diphthong' is directly derivable.

Etymology

The word diphthongize comes from the Greek parts di- meaning 'two' and phthong meaning 'sound', so it literally means 'to make two sounds'. That's why to diphthongize a vowel is to change a single vowel sound into two sounds when you say it.