What does phonology study?

Phonology is the branch of linguistics that studies the sound systems of languages. This includes the organization, distribution, and patterning of sounds. Phonology examines how phonemes (the smallest units of sound) function in particular languages and how they interact with each other. Understanding phonology is essential for grasping how sounds combine to form words and how these sounds can change in different linguistic contexts, such as accents and dialects.

The other choices refer to different areas of linguistic study: the structure of sentences is the focus of syntax, meaning in various contexts pertains to semantics or pragmatics, and the history of language development is studied in historical linguistics. These areas, while important, do not pertain to the specific study of sounds that phonology addresses.