|credit: Petr Kratochvil|
The term digraph comes from Greek δι (= twice) and γραφή (= writing). English has a lot of digraphs, eg. <ui> as in fruit, <oo> as in food or <sh> as in fish. There are trigraphs such as <tch> as in catch and even tetragraphs: <augh> or <ough> as in caught and bought. Pentagraphs ...? Maybe, if you accept the proper name Nietzsche in its English pronunciation. Heptagraphs ...? Can YOU find one in English?
Now that we know what a digraph in the linguistic sense of the term is, we can return to the problem of the ambiguous letter-to-sound relation of <th>, which I shall do in my next blog.