a combination of two vowels representing one sound.

a combination of two letters representing one sound.

any part of a word.

Any word that has a silent e sound.

Any two vowels together to make one sound.

Any two vowels in a word to make a long vowel sound.

Any two letters in a word that make one sound.

Any letter in a word that is in alphabetical order.

Diphthong

Digraph

Both diphthong and digraph

neither

Digraph

Diphthong

Digraph

Diphthong