Question

A verb form that functions as a noun is called a(n)

a) Adjective
b) Gerund
c) Adverb
d) Conjunction

Answer 1

C:Adverb
An adverb can function as a noun:
I need to visit him tomorrow.
Tomorrow is a thing, which makes it a noun. But since it tells us when, it is an adverb.

Answer 2

A gerund is an -ing verb that functions as a noun, and can be used as the subject of a sentence.

Step-by-step explanation:

Gerund Phrase

The gerund is defined as any -ing verb that functions as a noun. In other words, you can place a gerund phrase in any place in the sentence where a noun could normally function. When the gerund verb has an attendant object or modifiers, we describe it as a gerund phrase.

Example:

Eating an apple a day can keep the doctor away.

In this sentence, the word "eating" (which is formally defined as a verb) functions nominally (as if it were a noun) because it is the subject of the sentence.