What aspect of language pertains to the structure and rules governing such combinations?

The aspect of language that pertains to the structure and rules governing combinations of words is known as syntax. Syntax involves the arrangement of words and phrases to create well-formed sentences in a language. It dictates how different parts of speech (such as nouns, verbs, and adjectives) should be ordered and how they interact with one another to convey meaning.

For example, in English, the standard sentence structure is subject-verb-object (e.g., "The cat (subject) chases (verb) the mouse (object)"). Understanding syntax is essential for constructing grammatically correct sentences and for effective communication.

By contrast, phonology relates to the sounds of a language and how they are organized, semantics concerns the meaning of words and sentences, while pragmatics deals with the context of language use, including the intentions and social implications behind what is being communicated. Thus, syntax specifically addresses the systemic rules and structures that govern sentence formation.