The diagraph is a group of two letters that combined make just one phoneme or sound. This are some consonant digraphs: Bl, br, ch, cl, cr, dr, fl, fr, gl, gr, pl, pr, sc, sh, sk, sl, sm, sn, sp, st, sw, th, tr, tw, wh, wr.
In the following words you can find underlined the digraphs:
<u>Ch</u>aracterization [kar-ik-ter-uh-zey-shuhn, -truh-zey-]
Dia<u>ph</u>ragm [dahy-uh-fram]
Meta<u>ph</u>or [met-uh-fawr, -fer]
There also some words where a double consonant can also sound as one single phoneme, such as ss, mm, nn; however, for example, "misspell" which sound as [mis'spel] does not belong to this group, in this word the two “s” are pronounced separately.
In the following words you can find underlined the double consonants that make one sound:
Co<u>mm</u>unication [kuh-myoo-ni-key-shuh n]
Ra<u>pp</u>ort [ra-pawr, -pohr, ruh-]