What Is an Adjective Complement?

You know what an adjective is, but what is an adjective complement? Simply put, it’s a clause or phrase that modifies an adjective or adds to its meaning. An adjective complement can be a noun clause or a prepositional phrase.

What Is an Adjective Complement?

Adjective complements are an important aspect of English grammar. An adjective complement (also called an adjective phrase complement) is defined as a functional part of a sentence that completes the meaning of, or complements, an adjective or adjective phrase.

Adjective complements provide information that makes a word or group of words function as an adjective in a clause or sentence. They are usually paired with predicative adjectives, which are adjectives that come after a linking verb and describe the subject. If the meaning of an adjective is unclear as written, then an adjective complement is needed.

• If a sentence reads, "Barb is nervous," it conveys the idea that Barb is someone who tends to be nervous all the time.
• The word "nervous" is a predicate adjective because it is placed after a linking verb (is) and describes the subject (Barb).
• If the author or speaker isn't trying to say that Barb has a general trait of nervousness, then more information is needed to complete the meaning.
• The predicate adjective "nervous" can be clarified with the addition of an adjective complement.
• The sentence "Barb is nervous about public speaking" specifies the situation in which she is nervous.
  
• The addition of the adjective complement "about public speaking" completes the meaning of the adjective in this sentence.

Adjective complements can take the form of a noun clause or a prepositional phrase.

Adjective Complement as a Noun Clause

A noun clause is simply two or more words that function as a noun. It should have a subject and a verb, and, since it takes the place of a noun, it’s a dependent clause and cannot stand alone. A noun clause starts with the words “that," “how,” “if,” and the wh- words “what,” “when,” “why,” "who," and "where."

Examples of noun clauses include:

• when you arrived
• that he is happy
• where Sara went

Adjective Complement as a Prepositional Phrase

A prepositional phrase starts with a preposition — such as “with,” “about,” “on,” or “in” — and is followed by a noun, pronoun, noun phrase, pronoun phrase, or noun clause.

Examples of prepositional phrases include:

• with the car
• under the bridge
• after the show