Which subfield of linguistics deals with the rules regulating word structure?

Morphology is the subfield of linguistics that focuses on the structure of words and the rules that govern how they are formed. This includes the study of morphemes, which are the smallest units of meaning in a language. Morphology examines how these morphemes combine to create new words, including aspects such as prefixes, suffixes, and root words. Understanding morphology is essential for analyzing how different word forms convey specific meanings and grammatical functions within a language.

The other options represent different areas of linguistics. Phonetics focuses on the sounds of speech, phonology deals with the abstract sound systems and patterns within a language, and syntax involves the rules governing the structure of sentences and how words combine to form phrases and clauses. Each subfield contributes uniquely to the broader understanding of language, but it is morphology that specifically addresses word structure and formation rules.