What phonetic feature do the words "chow," "whoosh," and "stalk" have in common?

The correct choice is that the words "chow," "whoosh," and "stalk" contain digraphs. A digraph is a pair of letters that together represent a single sound. In "chow," the "ch" represents a single sound /tʃ/. In "whoosh," the "wh" produces the /w/ sound, while in "stalk," the "st" can be interpreted as a cluster but does not classify as a digraph by the same definition.

While the words are interesting for their other phonetic elements, such as the presence of distinct vowel sounds and consonants, the essential feature they share is the presence of digraphs, particularly in how they represent specific sounds. This phonetic characteristic plays a significant role in understanding how sounds are formed and represented in English, especially for learners of the language.