Complement

A:
Have you seen my umbrella?
B:
It’s downstairs, by the back door.
Playing the guitar always makes me happy.
Subject and object complements
In clauses with linking verbs (be, seem, become), complements which follow the verb and which add information about the subject are called subject complements:
Sheila is a nurse. (adding information about Sheila)
Sheila is a nurse. (adding information about Sheila)
All of them seemed surprised.
Complements which add more information about an object are called object complements:
He makes me very angry. (adding information about me)

Complements and adjuncts

Complements and adjuncts are different. A complement is necessary in order to complete the meaning. An adjunct is not necessary, and adds extra information.
Compare__Sheila_is_a_nurse'>Compare
Sheila is a nurse. (adding information about Sheila)
All of them seemed surprised.
Complements which add more information about an object are called object complements:
He makes me very angry. (adding information about me)


Complements and adjuncts
Complements and adjuncts are different. A complement is necessary in order to complete the meaning. An adjunct is not necessary, and adds extra information.
Compare

He put the cake in the oven. Not: He put the cake.	put must have a complement to say where something is put. Without the complement, the clause would not be complete.
We usually go away in the spring.	in the spring is an adjunct. It is not essential to complete the verb ‘go away’; it adds extra information.

By Richard Nordquist
Updated on January 11, 2020
an unclear area in linguistic analysis, and there are several unresolved issues In grammar, a complement is a word or word group that completes the predicate in a sentence. In contrast to modifiers, which are optional, complements are required to complete the meaning of a sentence or a part of a sentence.
Below you'll find discussions of two common types of complements: subject complements (which follow the verb be and other linking verbs) and object complements (which follow a direct object). As David Crystal has observed, in the "Dictionary of Linguistics and Phonetics":
"[T]he domain of complementation remains."


Subject Complements Examples
These are examples of subject complements. In this and the subsequent sections, the complement or complements are listed in italics.

• 
  My uniform is torn and dirty.
  
• 
  My uniform is a T-shirt and jeans.
  
• 
  "Imagination is the one weapon in the war against reality. – Jules de Gaultier
  
• 
  "Love is an exploding cigar we willingly smoke."– Lynda Barry
  

Object Complements Examples

• 
  Jimmy's teacher called him a troublemaker.
  
• 
  The teacher's remark made me angry.
  
• 
  "The widow she cried over me, and called me a poor lost lamb, and she called me a lot of other names, too."– Mark Twain, "Adventures of Huckleberry Finn"
  

Subject Complements Explanations
"Subject complements rename or describe the subjects of sentences. In other words, they complement the subjects.
"Many of these complements are nouns, pronouns, or other nominals that rename or provide additional information about the subject of the sentence. They always follow linking verbs. A less contemporary term for a noun, pronoun, or other nominal used as a subject complement is predicate nominative.

• 
  He is the boss.
  
• 
  Nancy is the winner.
  
• 
  This is she.
  
• 
  My friends are they.
  

"In the first example, the subject complement boss explains the subject he. It tells what he is. In the second example, the subject complement winner explains the subject Nancy. It tells what Nancy is. In the third example, the subject complement she renames the subject this. It tells who this is. In the final example, the subject complement they identifies the subject friends. It tells who the friends are.
"Other subject complements are adjectives that modify the subjects of sentences. They also follow linking verbs. A less contemporary term for an adjective used as a subject complement is predicate adjective.

• 
  My coworkers are friendly.
  
• 
  This story is exciting.
  

"In the first example, the subject complement friendly modifies the subject coworkers. In the second example, the subject complement exciting modifies the subject story."
_ Michael Strumpf and Auriel Douglas, "The Grammar Bible." Henry Holt, 2004
Object Complements
"An object complement always follows the direct object and either renames or describes the direct object. Consider this sentence:

• 
  She named the baby Bruce.
  

"The verb is named. To find the subject, ask, 'Who or what named?' The answer is she, so she is the subject. Now ask, 'Whom or what did she name?' She named the baby, so baby is the direct object. Any word following the direct object that renames or describes the direct object is an object complement. She named the baby Bruce, so Bruce is the object complement."
– Barbara Goldstein, Jack Waugh, and Karen Linsky, "Grammar to Go: How It Works and How to Use It," 4th ed. Wadsworth, 2013
"The object complement characterizes the object in the same way as the subject complement characterizes the subject: it identifies, describes, or locates the object (as in We chose Bill as group leader, We consider him a fool, She laid the baby in the crib), expressing either its current state or resulting state (as in They found him in the kitchen vs. She made him angry). It is not possible to delete the object complement without either radically changing the meaning of the sentence (e.g. She called him an idiot - She called him) or making the sentence ungrammatical (e.g. He locked his keys in his office - *He locked his keys). Note that be or some other copula verb can often be inserted between the direct object and the object complement (e.g. I consider him to be a fool, We chose Bill to be group leader, They found him to be in the kitchen)."
– Laurel J. Brinton and Donna M. Brinton, The Linguistic Structure of Modern English. John Benjamins, 2010