Which of the following best describes a conjunction?

A conjunction is defined as a word that serves to connect clauses, sentences, or words in a sentence. This connects parts of speech to improve the flow of writing and to show the relationship between those parts. For example, words like "and," "but," and "or" are common conjunctions that help combine ideas, making them clear and cohesive. Understanding this role is vital in constructing grammatically correct sentences where multiple ideas are presented and interrelated.

In contrast, options that describe other parts of speech highlight their specific functions: modifying verbs or nouns, showing relationships in time, or performing one of those particular tasks, which are not functions associated with conjunctions. Conjunctions specifically address the linkage of different parts within sentences, reinforcing the correct identification of their role in grammar.