Which term best describes the feature change [ +alveolar ] becomes [ +velar ]?

• A. Metathesis
• B. Insertion
• C. Deletion
• D. Assimilation

Answer: (D)

This is about place assimilation, where a sound takes on the articulatory place of a neighboring sound. When a feature that is [+alveolar] shifts to become [+velar], the segment is being shaped to resemble the nearby velar articulation. In coarticulation, the tongue position for one sound can move toward the place of articulation of the adjacent sound, and when this influence becomes phonologized, it’s described as assimilation. So the alveolar place changes to velar because of its context, making the sounds more alike and easing pronunciation.

Metathesis would involve swapping sounds or features, not changing the place of articulation of a single sound. Insertion would add a new segment, and deletion would remove one. Those don’t capture the idea of one sound becoming more like a neighboring one in place of articulation, which is exactly what assimilation describes.