In the first two terms of Reception, children learn approximately 44 sounds, also called phonemes (smallest units of sound that make up a word). Some phonemes consist of just one letter (e.g. j k e) and others consist of two/three letters (e.g. ch, sh, ure, igh) often referred to as digraphs (two letter sounds) and trigraphs (3 letter sounds).
Children are taught the phase 2 sounds (orange) first and then move onto learning the phase 3 sounds (purple) afterwards. Finally in Reception, children move onto phase 4 (green) where they read initial and end consonant blends. Generally speaking, children will start learning the phase 2 sounds in the Autumn Term and by the Spring term (April onwards) most children will have moved onto Phase 4.