Phonetics Glossary Homework
A diphthong is a special kind of vowel sound. Most vowel sounds in English are made with the
mouth in one position and with one pure sound. These vowel sounds are called monophthongs
(mono meaning “one” and phthong meaning “sound”). A diphthong is one vowel sound formed by
the combination of two vowel sounds. A diphthong begins as one vowel sound and moves toward
another, such as the vowel sounds in coin or loud. Diphthongs can be contrasted with two
monophthong vowel sounds together that form two syllables, such as in chaos, triage, or violin.
When teaching reading, the two vowel sounds most commonly identified as diphthongs are /oy/ and
/ow/. The most common spellings for the vowel sound /oy/ are oy (toy) and oi (void), and the two
most common spellings for /ow/ are ow (cow) and ou (cloud).
For the curious: a Youtube video by English Language Club https://www.youtube.com/watch?
v=d1HZPx8DuDw
Farrell, Linda. 2010
annaabi.ee 
