What is the function of the complement shown in parentheses in this sentence "The situation seems completely (desperate)" ?
The function of the adjective 'desperate' is as a predicate adjective, a type of subject complement.
A predicate adjective is an adjective that follows a linking verb , restating the subject of the sentence (situation).
A linking verb acts as an equals sign, the subject of the sentence is or becomes the object noun, pronoun, or adjective.
In the example sentence above, situation = desperate.
A subject complement can be a noun, a pronoun, or an adjective.
A noun or pronoun subject complement is call predicate nominative (or predicate noun).
An adjective subject complement is called a predicate adjective .