A DIGRAPH is a pair of letters representing a single sound—like ‘sh’.
A TRIGRAPH has 3 letters, like ‘tch’.
A TETRAGRAPH has 4 letters, like ‘eigh’.
Some languages have PENTAGRAPHS and HEXAGRAPHS—while the German word for beetroot soup, Borschtsch, contains a 7-letter HEPTAGRAPH. pic.twitter.com/CrrLTS8Cw1

— Haggard Hawks 🦅 (@HaggardHawks) December 5, 2021