The founder of Structural Grammar was—

The correct answer is Fries (Charles Carpenter Fries).

Explanation:

Structural grammar is an approach to analyzing language structure that focuses on the description of physical patterns, structure, and formal features of sentences rather than traditional prescriptive rules.

Charles Carpenter Fries (1887–1967) was an American linguist who established and pioneered the principles of Structural Grammar, most notably through his landmark work, "The Structure of English" published in 1952. In this work, he categorized words into structural classes based on their positions within sentence patterns rather than relying on traditional semantic definitions.