An adjective is a describing word. An adjective modifies a noun.
Usually an adjective is placed right next to the noun that is modifies, like this: I live in a red house. The adjective red modifies the noun house.
Sometimes the adjective is used as a predicate adjective. Then the adjective gets placed after the lining verb, like this: My house is red. The adjective red still modifies the noun house, but now it is linked to the noun house by the linking verb is.
Predicate adjectives always follow a linking verb. Look at these common linking verbs: is, are, was, were, seem, remain, grow
Here are more examples of sentences with a predicate adjective:
The box is large.
The dog was old.
My car is blue.
The old lady seems sad.
A predicate adjective modifies a noun, but it does not sit next to the noun in a sentence. A predicate adjective always follows a linking verb.
It’s your turn. Find the predicate adjective in this sentence: My teacher is happy. Did you figure it out? Good for you!