Which part of speech connects words, phrases, or clauses?

The correct answer is a conjunction. Conjunctions serve the essential function of connecting words, phrases, or clauses within a sentence, allowing for more complex and varied sentence structures. For example, in the sentence "I wanted to go for a walk, but it started to rain," the conjunction "but" connects two independent clauses, indicating contrast.

By using conjunctions, writers can effectively convey relationships between different parts of a sentence, enhancing clarity and coherence. Other parts of speech, such as prepositions, adverbs, and interjections, serve different functions in a sentence. Prepositions typically indicate relationships in time or space. Adverbs modify verbs, adjectives, or other adverbs to provide more detail. Interjections express strong emotions or sudden exclamations. Therefore, the unique role of conjunctions in binding various sentence elements together is what makes them the correct choice in this context.