Phonological Processes in Children's Speech
A phonological process is a systematic simplification pattern that a young child uses while learning to talk — an entire class of sounds is replaced, dropped, or shifted in a predictable way rather than a single word being mispronounced — and each pattern is expected to resolve by a predictable age as the child's speech develops.
The common patterns at a glance
Each row links to a full explainer below: what the pattern is, why it happens, how clinicians treat it, and what an automatic scorer can and cannot see.
| Process | Example | Typically resolves by |
|---|---|---|
| Fronting | cup → "tup" — /t ʌ p/ | around 3 years 6 months |
| Gliding | rabbit → "wabbit" — /w æ b ɪ t/ | around 6 to 7 years |
| Stopping | sun → "tun" — /t ʌ n/ | sound by sound, from about age 3 to about age 5 |
| Cluster reduction | spoon → "poon" — /p uː n/ | around 4 years for non-/s/ clusters, around 5 years for /s/-clusters |
| Final consonant deletion | cat → "ca" — /k æ/ | around 3 years 3 months |
The processes, one page each
Fronting
Typically resolves by around 3 years 6 months
Fronting is a phonological process in which a child replaces a sound made at the back of the mouth with one made at the front — most often /k/ becomes /t/ and /g/ becomes /d/, so "cup" is produced as "tup" and "go" as "doe".
Read the explainerGliding
Typically resolves by around 6 to 7 years
Gliding is a phonological process in which a child replaces a liquid consonant (/r/ or /l/) with a glide (/w/ or /j/) — "rabbit" becomes "wabbit" and "yellow" becomes "yeyow".
Read the explainerStopping
Typically resolves by sound by sound, from about age 3 to about age 5
Stopping is a phonological process in which a child replaces a fricative or affricate — a continuous, airflow-based sound like /s/, /f/, or /ʃ/ — with a stop consonant such as /t/, /p/, or /d/, so "sun" becomes "tun" and "fish" becomes "pit".
Read the explainerCluster reduction
Typically resolves by around 4 years for non-/s/ clusters, around 5 years for /s/-clusters
Cluster reduction is a phonological process in which a child simplifies a consonant cluster by deleting one of its consonants — "spoon" becomes "poon", "stop" becomes "top", and "blue" becomes "boo".
Read the explainerFinal consonant deletion
Typically resolves by around 3 years 3 months
Final consonant deletion is a phonological process in which a child omits the consonant at the end of a word, producing "cat" as "ca" and "dog" as "do".
Read the explainerA process is a pattern, not a single wrong sound
The distinction matters clinically. A child who mispronounces one sound in isolation has an articulation error. A child who applies the same simplification across a whole class of sounds — every velar fronted, every fricative stopped — has a pattern, and clinicians treat the pattern rather than each sound separately. That is why therapy for these patterns so often uses minimal pairs and cycles approaches rather than drilling one sound at a time.
It also changes what useful software looks like. Scoring a whole word tells you the word was wrong; scoring every phoneme in the word lets an application see that several velar targets in one session all scored low, which is the shape of a pattern rather than a one-off slip.