What is the primary function of pronouns in a sentence?

Pronouns primarily function in a sentence to replace nouns, allowing for smoother and more efficient communication. By substituting for nouns that have already been introduced or are understood from context, pronouns help avoid repetition and maintain clarity. For example, in the sentence “Maria loves her dog. She takes him for walks every day,” the pronouns "she" and "him" replace the noun "Maria" and the noun "dog," respectively.

This function of replacing nouns is crucial because it makes sentences less cumbersome and more cohesive, thereby improving the flow of writing and speech. Each of the other choices highlights different grammatical functions: indicating tense relates to verbs, modifying verbs refers to the action within the sentence, and connecting clauses involves conjunctions. These are important aspects of sentence structure, but they do not define the primary role of pronouns.