Here's why:
* Subject: The noun or pronoun that performs the action of the verb.
* Verb: The action word in a sentence.
* Predicate: The part of the sentence that tells us something about the subject. It includes the verb and any other words that describe or modify the subject.
Example:
* The dog is happy.
* Subject: Dog
* Verb: is
* Predicate: is happy
* Predicate Adjective: happy (modifies the subject "dog")
The adjective "happy" is in the predicate position because it follows the verb "is" and describes the subject "dog."