What is a gerund?

A gerund is a verb form that ends in -ing and functions specifically as a noun within a sentence. This means that even though it is derived from a verb, it takes on the role that a noun typically would, such as being the subject, object, or complement of a verb.

For example, in the sentence "Swimming is fun," the word "swimming" is a gerund because it ends in -ing and serves as the subject of the sentence. Similarly, in "I enjoy reading," "reading" acts as the object of the verb "enjoy."

Understanding gerunds is essential for constructing grammatically correct sentences and for enhancing writing clarity, as they allow for the expression of actions in a noun-like capacity. The other options describe different grammatical concepts and do not accurately define what a gerund is.