1. Gerunds

2. Gerunds and Gerund Phrases
A Gerund is a Verbal which which always end in –ing.
 A Gerund is used as a Noun. (Not to be confused with a Participle which is used as an adjective)
A Gerund can be used as a Subject, Subject Complement, Direct Object, Indirect Object, or Object of a Preposition in a sentence.

3. Example: Taking classes can be enjoyable.
Gerund (Acting as a Subject)
Direct Object for Gerund (Taking What?)
Helping Verb
Verb
Subject Complement (Predicate Adjective)

4. To diagram a Gerund:
Since Gerunds function as Nouns, they are placed on a stepped line atop a pedestal above the base line where a noun would normally appear.
The stepped line is then extended to include any objects or complements.
Here is the formula:

5. Final Product of the Example: Taking classes can be enjoyable.

6. Practice:
Matthew helped his father by washing the car after school.

7. Teresa enjoys reading historical novels.

8. Drinking water is good for you.

9. Freedom is knowing the truth.