What does an interjection express?

An interjection is a word or phrase that expresses a strong emotion or exclamation. It is often used to convey feelings such as surprise, joy, anger, or excitement. Interjections are typically standalone words or phrases that can be inserted into a sentence without altering its grammatical structure. For instance, words like "wow," "ouch," or "hey" serve as interjections that express distinct emotions.

This understanding of interjections clarifies their role in language, differentiating them from other parts of speech. Unlike conjunctions, which connect sentences, or adjectives, which describe nouns, interjections focus primarily on conveying emotional reactions rather than providing information about the elements within a sentence. This unique function of interjections makes option C the correct answer.