A gerund is a word that begins with a verb and ends in -ing. Wait a minute! Isn’t that what a present participle is? Glad you were paying attention. Now for the rest of the story. A gerund begins with a verb, ends in -ing, and acts like a noun (that is, it names a person, place, or thing).
Running up hills for the last six months has improved Cathy’s stamina.
Running is a gerund. It’s composed of a verb (run), ends in -ing, and is used as a noun.
Gerunds can appear by themselves or they can be part of a larger gerund phrase, but either way they function as nouns.
Blowing bubbles on a windy day can be disastrous.
Blowing bubbles on a windy day is the gerund phrase subject of the verb can be.
Greg hates running on a treadmill.
Running on a treadmill is a gerund phrase that is the direct object of hates.
You should always put the possessive noun or possessive pronoun (my, your, his, her, its, our, and their) before a gerund. For some reason this rule is often ignored or misunderstood by many people, but it is proper grammar. Look at this sentence:
David continues to be amazed by (Susan, Susan’s) singing.
Use the possessive Susan’s before the gerund singing.
The same is true for this sentence:
Steve and Diana weren’t happy about (us, our) leaving so early.
Use the possessive pronoun our before the gerund leaving.
Grammar Facts
Look at the different uses of addressing in these sentences:
Addressing the problem made Pat Davis realize what she must do.
Addressing the audience, Donna and Jim White felt a connection.
Anthony and Ruth Hazelwood mailed the invitations as soon as they finished addressing the envelopes.
In the first sentence, addressing is a gerund (a verb plus -ing, functioning as a noun). In the second sentence, addressing is a participle (a verb plus -ing, functioning as an adjective). In the last sentence, addressing is a verb (showing action).
Though not common, gerunds can occasionally create new compound verbs. Take for example the compound gerunds bar-tending or baby-sitting. These gerunds are composed of two parts, “bar” “tending” and “baby” “sitting.” You could also divide these gerunds as “bartend” plus “–ing,” and “babysit” plus “–ing.” Since “-ing” is a suffix for verbs, “bartend” and “babysit” must be verbs. After all, Paul can bartend on Friday nights, and Frannie can babysit next week, so we have gerunds that have become new verbs. This process is called reanalysis, and while not very common does sometimes occur.