17. Gerund Phrases

Change from full subject-predicate form
The verb in gerund phrase is reduced to participial forms way function as gerund except the-ed past participle; the most common form, however, is the-ing present participle.
The subject of a gerund may be found in another part of the sentence or it may be understood. A subject that is contained within the gerund phrase takes inflected possessive form, prepositional form, or unchanged form. The object of a gerund is unchanged or is contained within an of phrases. By means of such changes in the nominal elements of a simple sentence, these elements may be strung along after the verb as prepositional phrases. Thus, the simple sentence The hunters shot the birds can be come the gerund phrase The shooting of the birds (original object) by the hunters (original subject).
These changes from subject-predicate form also permit the gerund phrase to be embedded as a noun within another predication-The shooting of the birds by the hunters cause her great distress. The gerund functions as noun head of the gerund phrase, the transformed subject and object as adjectival modifiers.

Nominal functions of gerund phrases