What Are Subject and Object Complements?

Introduction to Complements

The word "complement" means "something that complements or gives a sense of completion to something else". Complements, along with subjects, verbs, objects, and adjuncts, form one of the five major elements of clause structure. While a subject complement helps make the subject complete, an object complement works hard to complement an object. In both cases, a complement is part of the predicate of a sentence. Being able to instantly identify and efficiently use complements is an integral part of students' grammar learning.

What Is a Subject Complement?

A subject complement, also called a subjective complement, is a word, phrase, or clause that follows a linking verb and describes or identifies the subject in a sentence.

Examples of Subject Complements

The dish tasted sweet. (The word "sweet" follows the linking verb "tasted" and describes the subject "the dish".

Dad is upstairs. (The adverb "upstairs" follows the linking verb "is" and tells where Dad is.)

Frederick has become a renowned writer. (The phrase "a renowned writer" is the subject complement in this sentence.)

The problem is that I can't focus on my lessons. (The clause "that I can't focus on my lessons" is the subject complement here.)

Karen felt tired after her swimming lessons. (The word "tired" is the subject complement in this sentence.)

The recipe still remains a secret. (The phrase "a secret" is the subject complement in this sentence.)

Pronouns as Subject Complements

We sometimes use a pronoun as a subject complement after a form of "be". In such cases, we use an object pronoun in a less formal context and a subject pronoun in a formal context. Examples of subject pronouns are "you", "she", "I" and "they". Examples of object pronouns are "you", "her", "me", and "them".

Examples:

Mom opened the door before I even rang the doorbell. She knew it was me. (less formal)
Mom opened the door before I even rang the doorbell. She knew it was I. (formal)

Are you sure it was him who sold you the fake product? (less formal)
Are you sure it was he who sold you the fake product? (formal)

Subject Complements and Linking Verbs

A subject complement works only with a linking verb and never with an action verb. Remember, some verbs like "am", "was", and "is" (forms of "be") always function as linking verbs, so they are pretty much a cakewalk. The catch is verbs such as "appear", "smell", and "taste" can be both action and linking verbs. So, before using a subject complement with one of these, be sure the verb is used to link and doesn't denote an action.

Examples:

Marjorie was excited about the weekend trip to the zoo. ("Was" is a form of "be".)

Before teaching English, John had been a salesman for three years. ("Had been" is another form of be.)

Rhonda smelled the fresh flowers. (This "smelled" is an action verb, so there is no subject complement.)

The flowers smelled good. (This "smelled" is a linking verb, so there is a subject complement: good.)

Predicate Nominatives

If the subject complement is a noun, it's called a predicate nominative. A predicate nominative renames the subject.

Examples:

This place was a desert.

Kimberly is a doctor.

The Turners are teachers.

Predicate Adjectives

If the subject complement is an adjective, it's called a predicate adjective. Like an adjective, a predicate adjective describes or gives more information about the subject.

Examples:

Michelle sounded intelligent.

The test proved challenging.

The class suddenly fell silent.

What Is an Object Complement?

There are three things that help us identify an object complement or objective complement. It is a noun or an adjective that follows a direct object. It renames the object or states what it has become. The verb that an object complement follows must be a transitive active verb.

Examples of Object Complements

The long homework made Edward frustrated. (The adjective "frustrated" is an object complement as it states what "Edward", the object, has become. There is a transitive verb: made.)

The company appointed Sharon the sales director. (The noun phrase "sales director" is an object complement as it states what "Sharon", the object, has become. There is a transitive verb: appointed.)

We called our son Alexander. (The noun "Alexander" is an object complement as it renames "son", the object. It follows a transitive verb: called.)

The team considered the new idea interesting. (The adjective "interesting" is an object complement as it states how the idea is considered. It follows a transitive verb: considered.)

Complements vs. Adjuncts

A complement is necessary for the meaning of a sentence to be complete. An adjunct is not essential to complete the meaning; it only adds extra information.

Examples:

Greed for money made the brothers enemies. (The meaning is not complete without the complement: enemies.)
Greed for money made the brothers enemies forever. (The adjunct "forever" is not essential to complete the meaning.)

Smith considered Hall his best friend. (The meaning is not complete without the complement: his best friend.)
Smith and Hall greatly trust each other. (The adjunct "greatly" is not essential to complete the meaning.)

Direct Objects vs. Object Complements

A common mistake students are likely to make is to confuse the two sentences: a sentence with an indirect object and a direct object and a sentence with a direct object and an object complement. This is because at first glance both the sentences look a lot similar to each other. By carefully analyzing lots of sentences from the two categories, they can be conversant with the two structures. The key is to revisit the three rules that help identify an object complement.

Examples:

Dad gave me a pen. (The sentence has an indirect object and a direct object.)
Dad called my brother Ben. (The sentence has a direct object and an object complement.)

Cassandra wished me good luck. (The sentence has an indirect object and a direct object.)
Cassandra kept the room clean. (The sentence has a direct object and an object complement.)

---