Spelling test -9-
A diphthong is a sound made by combining two vowels, specifically when it starts as one vowel sound and goes to another. The vowel sound that you hear in cow is /ou / spelled ow. The vowel sound you hear in loud is /ou / spelled ou. The vowel sound that you hear in boil is /oi/ spelled oi. The vowel sound you hear in boy is /oi/ spelled oy.