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 like)
She had a suggestion to offer. (adjective modifying suggestion)
He called to warn her. (adverb modifying the verb called)
A participle is a verb that ends in -ing (present participle) or -ed, -d, -t, -en, -n (past participle). Participles may function as adjectives, describing or modifying nouns.
The dancing parrots entertained the crowd.
The wrecked sailboat washed up on shore.
But participles have another function. When used with helping verbs such as to be and to have, they are action verbs and form several verb tenses.
She is thinking of the children.
The conference room had been cleaned before they arrived.