What is true about gerunds?

Gerunds function as nouns derived from verbs, which is why the answer is correct. In English grammar, a gerund is formed by adding the “-ing” ending to a verb (for example, “swimming” from the verb “swim”). Although gerunds retain properties of verbs—such as taking objects and being modified by adverbs—they primarily act as nouns within sentences. For instance, in the sentence “Swimming is fun,” "swimming" serves as the subject of the sentence and behaves like a noun.

Understanding gerunds is crucial for language learners because they allow for a smoother flow in expressing actions or activities as subjects, objects, or complements. This understanding aids in constructing more complex and varied sentences in both spoken and written English.