A diphthong is a vowel sound made by sliding from one vowel sound to another in the same syllable. Instead of one steady sound, the mouth moves as you say it. These vowel teams create a blended sound that is not exactly like either vowel alone.
Think of diphthongs as “gliding vowels.” Your mouth moves as you say them. Practice slowly stretching the sound to feel the glide.
The diphthongs oi and oy make the same sound you hear in “coin” or “boy.” Both spellings create the same vowel glide.
Use oi in the middle of a word and oy at the end of a word. Both spellings sound the same.
The diphthongs ou and ow make the sound you hear in “out” and “cow.” Both spellings glide from one vowel sound to another.
Both ou and ow can be used at different places in a word. Ow often comes at the end, and ou is usually in the middle.
The diphthongs au and aw usually make the sound you hear in “saw” or “autumn.” The vowel sound is open and rounded.
Aw often comes at the end of words, while au usually appears in the middle. Listen carefully for the rounded vowel sound.
Diphthongs are vowel teams that create a gliding sound, moving from one vowel to another. The main patterns are oi/oy, ou/ow, and au/aw.
When reading, try the diphthong sound first. Remember: diphthongs slide from one vowel to another in a single syllable.