Appositive and predicate nominative

Appositive

Pronouns are sometimes used with a noun appositive to determine the right case form.
A noun appositive is a noun or pronoun that follows another noun or pronoun to identify or explain it.
An appositive will always come after the noun or pronoun it explains.
Ex: Esther, a Western Illinois University, is teaching at Macomb Middle School.

Example

Esther, a Western Illinois University, is teaching at Macomb Middle School
Where is the appositive? The appositive follows the noun it identifies ( Esther)
* Separated by commas

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Predicate Nominative

The predicate is the part of a sentence that tells what the subject does or is.
Ex: She was a monster.
Sentence pattern: Subject, Linking verb, predicate Nominative
Linking verbs, such as "is," "are," "was," and "were," connect the subject to a subject complement (which can be a noun or an adjective that describes or identifies the subject).

A monster she was
beautiful are the stars