Gerunds are words that are formed from verbs but act as nouns.
You can spot them because they will be a verb + ing acting as a noun.
Swimming is fun.
The word swim is a verb. Swimming is a verb with an -ing ending acting as a noun. It is the subject of this sentence.
Tip: Words that are formed from verbs but don't act as verbs are called verbals. There are two other types of verbals: participles and infinitives.

They can do anything that nouns can do. That means that they can be subjects, direct objects, objects of prepositions, predicate nouns, and more!
These consist of a gerund and the words that modify and complement it.
Swimming in the pool is fun.
Gerund |
Phrase |
| my favorite activity. |
|
Modifiers
You remember what these act as NOUNS, right? Of course you do.
You also remember that nouns are modified by adjectives, right? If you aren't comfortable with that yet, you should probably be reading up on the eight parts of speech.
Adjectives and adverbs are called modifiers because they modify (describe) other words.
Okay, let's get back to the matter at hand. Let's look at one of those examples from above.
Swimming in the pool is fun.
You may have noticed that in the pool is an adverbial prepositional phrase. It is telling us where the swimming happened.
(Where is an adverb question. You can read up on those on the adverbs page!)
You should now be saying to yourself, "Hey! Nouns can only be modified by adjectives. What gives, Elizabeth?"
Here is what gives. ---> Gerunds are formed from verbs.
Even though they are officially nouns, they still carry some of the attributes of verbs.
Their "verbness" allows these guys to take adverbial modifiers just like any other verb - even though they act as nouns. (By the way, they can still take adjectival modifiers just like other nouns.)
Gerunds can even do other verby things...
Complements
Complements are things like direct objects. They complete verbs.
Guess what?
These babies can have complements!
Running marathons is my favorite activity.
Marathons is the direct object of running.
"Subjects"
Are you ready to hear something kind of strange? They can even have subjects... sort of.
Subjects are usually in the subject case (I, he, she), but these subjects will always be in the possessive case (his, her, my).
His snoring keeps me awake.
His is the "subject" of snoring.
In a Sentence... |
Acting As... |
Its Complement/ Modifier... |
| Diagramming sentences is fun! | Subject | Sentences is the direct object of diagramming. |
| I love listening to my favorite band. | Direct Object | To my favorite band is a prepositional phrase modifying listening. |
| Mary's loud eating really bothers me! | Subject | Mary's is the "subject" of eating Loud is an adverb modifying eating. |
These sit on steps when you diagram them.
The verb part goes on the top part of the step, and on the -ing goes on the bottom part of the step.

After that, you diagram the modifiers and complements just as you would with any other word.
|
If you want to teach or learn grammar the easy way, then follow a step-by-step program that clearly lays everything out for you and allows you to move at your own pace. The Get Smart program is presented in a meaningful sequence, so it's not an overwhelming mishmash of information. Before you know it, you'll be a grammar and sentence diagramming pro! |
![]() Elizabeth O'Brien is the creator of the Grammar Revolution step-by-step grammar and sentence diagramming programs. Her programs are guaranteed not only to teach you grammar, but also to give you more confidence in your communication skills. |
To get your free Parts of Speech guide and receive Elizabeth's bi-weekly articles on improving your grammar and having fun with sentence diagramming, enter your email address and name below right now. |
![]() |
![]() |
![]() |
![]() |

Beginner Level
Beginner's Deluxe Program
Teach yourself or your students grammar and sentence diagramming in ten minutes a day! Start immediately.
Beginner's Basic Program
Learn how to diagram sentences.
All Levels
The Perfect Supplement
Look up topics, learn about them, and see how they are diagrammed.
Advanced Level


Advanced Program ANSWER KEY & WORKBOOK
Keep your grammar and diagramming skills sharp!
