Verbals: Gerunds, Infinitives, and Participles The three verbals— gerunds, infinitives, and participles —are formed from verbs, but are never used alone as action words in sentences. Instead, verbals function as nouns, adjectives, or adverbs. These verbals are important in phrases. The gerund ends in -ing and functions as a noun. Jumping is fun. He liked skiing . He had a unique way of whistling . The infinitive is the base form of a verb with to . Usually it functions as a noun, although it can also function as an adjective or adverb. To jump is fun. (noun; subject of the verb is ) I like to ski . (noun; direct object of the verb lik...