Which error pattern would best indicate motor planning difficulty rather than a primary language impairment?

• A. Frequent, consistent grammatical errors in sentence production.
• B. Normal comprehension with fluent speech.
• C. Inconsistent sound errors across words.
• D. Good naming performance with fluent repetition.

Answer: (C)

The key idea is that motor planning problems show up as variability in how sounds are produced, rather than a fixed rule-based error pattern. When the brain struggles to plan the sequence of movements for speech, the same word can be produced differently on different attempts, with substitutions, distortions, or timing variations that aren’t consistent from trial to trial. That kind of inconsistency is the hallmark of motor planning difficulty.

So, inconsistent sound errors across words best indicate a motor planning issue rather than a primary language impairment because they reveal trouble with programming articulatory sequences rather than with grammar, comprehension, or lexical retrieval.

Frequent grammatical errors point to syntactic or morphological language processing, not motor planning. Normal comprehension with fluent speech suggests language understanding is intact and fluency isn’t impaired in a way that highlights motor planning problems. Good naming with fluent repetition implies preserved lexical retrieval and motor sequencing, not a breakdown in planning.