A 6-year-old girl consistently produces /l/ → [w]. In this case, the type of segment error that she produces is ...

• A. Typical because 90% of 6-year-old girls produce this type of substitution.
• B. Nondevelopmental because it has persisted past the normal limit of acquisition for /l/.
• C. Developmental because she is younger than the expected age of acquisition for the /l/ phoneme.
• D. Atypical because fewer than 5% of children age 3 to 8 years produce this kind of error.

Answer: (B)

The key idea is how we classify errors based on age and persistence. Substituting the liquid /l/ with a glide like [w] is a common simplification in early speech development, often called gliding. But when a child continues to produce /l/ as [w] beyond the age when most children have mastered /l/, that pattern isn’t just a typical developmental stage—it’s considered nondevelopmental because it persists past the normal window for acquisition. In this case, a 6-year-old showing this substitution indicates that the /l/ sound has not reached typical, age-expected mastery, so the error fits the nondevelopmental category.

This isn’t best described as typical, since most children have either mastered /l/ or are near mastery by this age. It isn’t developmental for the same reason: the pattern is beyond the usual age range for acquiring /l/. And while we could discuss rarity, the defining criterion here is retention past the normal acquisition timeline, which is why the nondevelopmental label is the most accurate.