Words are made up of different sounds, or phonemes.

The word cat can be split into three phonemes.

c-a-t

The word thrush can be split into four phonemes.

th-r-u-sh

Sometimes two or more letters are needed for one phoneme. Two letters that make one phoneme is called a digraph. Three letters that make one phoneme is called a trigraph.

If you can split words into phonemes it helps with reading and spelling.