Glossary · Letters, phonics and word reading
What is a consonant cluster?
Definition
A consonant cluster is a group of consonants with no vowel between them, such as the str in street or the nds in hands.
Cluster is the broader term. It covers blends, where every sound is heard, and groups that include a digraph, like the nch in bench (/n/ plus /ch/) or the thr in three (/th/ plus /r/).
English allows big clusters. Up to three consonants can start a word (spring, scrap, splash), and up to four can end one (texts). Most other languages allow far fewer, which is why students learning English as a new language often add a vowel to break a cluster up.
For teaching, the key is still counting sounds. In thr there are two sounds and three letters. Sound boxes make that clear: th goes in one box, r in the next.
In a lesson
Draw boxes for throb. The student says /th/ /r/ /ŏ/ /b/ and writes th in one box, r in the next. Four sounds, five letters, one cluster of two sounds at the start.
Examples
Each word with its spelling units, one per sound.
- throbth·r·o·b
- springs·p·r·i·ng
- scraps·c·r·a·p
Words come from our lexicon, checked against a pronouncing dictionary. Words a student sees in our assessments are left out.
Why does this matter for the record?
Clusters with a digraph inside cause their own errors. Note them separately from simple blends if a student keeps writing tr for thr.
Rate each skill as you teach it
Needs support, Developing, Secure. The rating schedules the review and builds the report.