What does morphology study in language?

Morphology is the branch of linguistics that focuses specifically on the structure and formation of words within a language. It examines how words are constructed from smaller units known as morphemes, which are the smallest meaningful units of language. This involves understanding prefixes, suffixes, roots, and how they combine to create new words or alter their meanings.

For example, the word "unhappiness" can be broken down into the morphemes "un-" (a prefix meaning 'not'), "happy" (the root word), and "-ness" (a suffix that turns an adjective into a noun). This illustrates how morphology studies the internal structure of words and the way that different morphemes contribute to the overall meaning of a word.

The other options refer to different aspects of language. The sound system of language pertains to phonology, the study of sound patterns and systems. The meaning of words and phrases relates to semantics, which focuses on what words and phrases signify. Rules for word order in sentences are part of syntax, which deals with how sentences are structured grammatically.