The morphophonemic process observed when the plural inflection of pictures, frames, malls, clothes is pronounced as [z] is called ____.

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

Answer: (A)

Voicing assimilation is at work here. In English, the plural ending -s can be pronounced as [s], [z], or [ɪz], and which one you hear depends on the sound before the suffix. When the stem ends in a voiced sound, the plural morpheme takes a voiced like [z] so the voicing spreads from the preceding sound to the suffix. That’s why words like pictures, frames, malls, and clothes are heard with a [z]-like ending—the voicing of the previous consonant influences the plural suffix. This spreading of a feature from a neighboring sound is assimilation. The other processes—dissimilation (making sounds less alike), metathesis (reordering sounds), and insertion (adding a sound)—don’t describe what’s happening here.