What is the name of a word that links two or more sentences into a single sentence?

The term that refers to a word used to link two or more sentences into a single sentence is a conjunction. Conjunctions serve the primary purpose of connecting clauses, phrases, or words, enabling complex and compound sentences. This allows for smoother transitions in thought and enables the combination of related ideas into a coherent statement.

In contrast, adverbs modify verbs, adjectives, or other adverbs, providing additional detail about how something is done but do not serve to connect sentences. Prepositions indicate relationships between nouns (or pronouns) and other words in a sentence, often relating to time, place, or direction, rather than linking sentences. Pronouns replace nouns in sentences, allowing for more concise expression but are not used to join separate sentences together. Thus, the use of conjunctions is essential in constructing meaningful, interconnected statements in writing.