What Is a Digraph
A digraph is two letters that represent a single sound. The most common examples are consonant digraphs like 'sh' in "ship," 'ch' in "chair," 'th' in "this," and 'wh' in "when." Vowel digraphs like 'ea' in "read" and 'oa' in "boat" follow the same principle but involve vowels instead.
Digraphs are foundational to phonics instruction because they violate the basic rule that each letter makes one sound. A struggling reader who doesn't recognize 'sh' as a single unit will try to blend '/s/' and '/h/' separately, which doesn't work. This is why explicit digraph instruction appears in most structured literacy programs, including Orton-Gillingham based approaches and foundational reading curricula aligned with the Science of Reading.
For children with dyslexia or reading deficits, digraph mastery is often a prerequisite skill. Many IEPs include specific benchmarks for digraph fluency, typically expecting automatic recognition by the end of first grade for common consonant digraphs.
How Digraphs Are Taught
Explicit digraph instruction typically follows this sequence:
- Sound isolation: Students hear and repeat the digraph sound in isolation, then in initial, medial, and final word positions.
- Letter pairing: Students see the two letters together and learn they create one sound, not two.
- Blending practice: Students blend digraphs with other sounds to decode real words: 'sh' + 'op' = "shop."
- Automaticity: Repeated exposure builds fluency so students recognize digraphs instantly without conscious effort.
In Orton-Gillingham methodology, digraphs are typically introduced after students master single consonant and vowel sounds. This multi-sensory approach involves saying the sound, writing the letters, and using tactile materials to reinforce the digraph concept.
Digraphs vs. Other Blends
Parents and educators often confuse digraphs with blends. A digraph makes one new sound that's different from its component letters ('sh' doesn't sound like '/s/' + '/h/'). A blend combines two consonant sounds that are both pronounced: 'st' in "stop" preserves both the '/s/' and '/t/' sounds. A trigraph takes this further, using three letters for one sound, like 'tch' in "catch."
Vowel digraphs can be trickier to teach because they often have multiple pronunciations. 'ea' sounds like '/ee/' in "bead" but like '/eh/' in "bread." Many literacy programs teach vowel digraph patterns in sets based on pronunciation patterns.
Common Questions
- How do I know if my child hasn't mastered digraphs? Listen for decoding errors like saying "/ch/ /i/ /p/" for "chip" instead of reading it as a whole word. Reading below grade level by the second half of first grade can indicate slower digraph automaticity. A reading specialist can assess this formally.
- Should digraphs be taught before blends? Most structured programs teach digraphs first because they represent single units, making them conceptually simpler. Once digraph automaticity is solid, blends are easier to understand as two distinct sounds.
- Are digraphs included on reading assessments? Yes. Most universal screeners at grades K-2 include digraph decoding items. Progress monitoring for students with IEPs typically tracks digraph fluency explicitly, measuring accuracy and speed.
Related Concepts
Understanding digraphs becomes clearer when you also explore Consonant Digraph, Vowel Digraph, and Trigraph. Each represents a distinct type of multi-letter sound unit used in phonics instruction.