How do I tell if it’s CAS or phonology?

Childhood Apraxia of Speech (CAS) and phonological disorders can be differentiated through careful clinical assessment of speech patterns and motor planning abilities.

CAS is a motor speech disorder. The core difficulty lies in planning and coordinating speech movements, rather than learning sound patterns.

Features more consistent with CAS include:

• inconsistent errors across attempts

• difficulty with longer or more complex words

• disrupted transitions between sounds and syllables

• increased errors as length and complexity increase

In contrast, phonological difficulties tend to present with more consistent, rule-based error patterns.

In clinical practice, differentiation is often supported through dynamic assessment. Observing how a child responds to cueing, modelling and adjustment of word structure can provide valuable information about whether the underlying difficulty is primarily motor planning or phonological.