Which part of speech is primarily responsible for connecting sentences or clauses?

Conjunctions are primarily responsible for connecting sentences or clauses, making them an essential part of sentence structure. They serve to link words, phrases, and clauses, allowing for the construction of complex and compound sentences. For example, in the sentence "I wanted to go for a walk, but it started raining," the conjunction "but" connects two independent clauses, demonstrating how they can convey a relationship between two ideas.

Other parts of speech, such as nouns, adverbs, and prepositions, have different roles. Nouns function as subjects or objects within a sentence, adverbs modify verbs, adjectives, or other adverbs to provide additional details about the action or characteristics, and prepositions show the relationship between a noun (or pronoun) and other words in a sentence. While these parts of speech each play important roles, they do not primarily serve to connect sentences or clauses like conjunctions do.