Complements

Complements are one of the five major elements of clause structure. The other four are subject, verb, object and adjunct (complements are in bold):

Both the brothers became doctors.

A:
Have you seen my umbrella?

B:
It’sdownstairs, 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)

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.