Illinois Reading Specialist Practice Test

Diphthongs are characterized by the movement or glide from one vowel sound to another within the same syllable. This means that when pronouncing a diphthong, the speaker begins with one vowel sound and transitions smoothly into another, creating a blended sound. This glide is a defining feature that differentiates diphthongs from other types of vowel sounds.

For example, the diphthong in the word "coin" starts with the vowel sound /ɔɪ/ and moves toward /ɪ/, showcasing this dynamic shift in sound. Recognizing that diphthongs are the combination of two vowel sounds is crucial for understanding phonetics and teaching reading and phonology effectively.