Digraphs and blends can easily be confused because both digraphs and blends consist of two letters to make a sound.
But there is a BIG difference between a digraph and blend…
A digraph contains two consonants and only makes one sound such as sh, /sh/. (ch, wh, th, ck)
A blend contains two consonants but they each make their own sound, such as /s/ and /l/, /sl/ (st, fl, sk, gr, sw, ect.)
Put simply each sound can be heard in a blend, but you cannot hear both letters in a digraph. No matter the type of Phonics Program you use, e.g. Letters and Sounds, Dianna Rigg, Jolly Phonics, Soundwaves, Thrass, children should be shown that the same sound can be represented in a different way. For example, pay, aim gray, all have the /ai/ sound but they use a different digraph.
Here’s some examples of Consonant digraphs and vowel digraphs…