In general, a predicate completes a sentence by providing information about what the subject is or does. The subject of a sentence is who or what is doing the action. The predicate explains the action. There’s often a linking verb (like is or became) in between the two. A predicate nominative is a noun that completes the linking verb in a sentence. Predicate adjectives complete the linking verb by describing the subject of a sentence. Sound complicated? Let’s break it down.
Linking Verbs
This will make a lot more sense if we talk about linking verbs first. Linking verbs connect the subject of a sentence to a predicate without conveying any action. They just describe or identify the subject. For instance, “The snowman looks awesome.” Looks is the linking verb in this case because it “links” the subject (snowman) to the adjective describing it (awesome). Some linking verbs have to do with states of being, like am, is, was, were, and will be. Others relate to the five senses: feel, taste, appear, smell, and sound.
Predicate Nominatives
Now that you have a good handle on linking verbs, let’s get into predicates. The predicate nominative (or predicate noun) is the noun or pronoun that comes after a linking verb. It renames the subject of the sentence. The sentence should still make sense if you switch the predicate nominative and the subject.
One way to see if a sentence includes a predicate nominative is to substitute the verb with the word equals. If the basic meaning of the sentence stays the same, then it contains a predicate nominative. For example, “Ben is a fireman” can read “Ben equals a fireman” without changing the point. In this example, fireman is the predicate nominative.
Predicate Adjectives
Like the other adjectives we know and love, predicate adjectives describe things.Predicate adjectives also tend to appear after a linking verb and provide more information about the subject of a sentence. For example, in “Jack is handsome,” Jack is the subject, and handsome is the predicate adjective.
In some cases, there might even be multiple predicate adjectives in the same sentence. For example, in I Know Why the Caged Bird Sings, Maya Angelou writes, “I was happy, Dad was proud, and my new friends were gracious.” This sentence has three predicate adjectives, each located after a linking verb. Each describes one of the subjects in the sentence. Predicate adjectives typically complement the linking verbs be, become, make, seem, or feel.
A single sentence can contain both predicate nominatives and predicate adjectives. For example, “She’s an engineer and is happy.” Here, the predicate nominative is engineer and the predicate adjective is happy.
You don’t have to follow a strict rule about whether to include one or both of these tools in a sentence. It’s just useful to understand the inner workings of it all.