I want to check my understanding of these 2 terms:
diphthong (concerned with sound; 1 sound; represented 2 letters; not long or short)
digraph (concerned with graphemes; 2 letters; can be long or short)
Is this accurate? If not what is the similarities/differences? And can a diphthong be represented by a digraph/ is it always represented by a digraph?
You are right about their being concerned with sound and graphemes, respectively.
A diphthong is concerned in particular with vowels. The term refers to a combination of two vowels characterized by a sort of glide from one vowel to the other. English is full of them, and particularly in English it is not true that a diphthong is always represented by two letters. Here are some examples:
a in "gate" /eɪ/
i in "bite" /aɪ/
o in "alone" /əʊ/ (BE) or /oʊ/ (AE)
ow in "cow" /aʊ/
A digraph is any two-letter representation of a single sound. Examples:
th in "another" /ð/ or in "thanks" /θ/
sh in "English" /ʃ/
oo in "root" /u/
The diphthong /aʊ/ in "cow" is represented as the digraph "ow". This is not unusal, but as you can see in the examples, not always the case.Tweet