In grammar

Grammar

In linguistics, grammar is the set of structural rules that govern the composition of clauses, phrases, and words in any given natural language. The term refers also to the study of such rules, and this field includes morphology, syntax, and phonology, often complemented by phonetics, semantics,...

, a predicative is an element of the predicate

Predicate (grammar)

There are two competing notions of the predicate in theories of grammar. Traditional grammar tends to view a predicate as one of two main parts of a sentence, the other being the subject, which the predicate modifies. The other understanding of predicates is inspired from work in predicate calculus...

 of a sentence

Sentence (linguistics)

In the field of linguistics, a sentence is an expression in natural language, and often defined to indicate a grammatical unit consisting of one or more words that generally bear minimal syntactic relation to the words that precede or follow it...

 that supplements the subject

Subject (grammar)

The subject is one of the two main constituents of a clause, according to a tradition that can be tracked back to Aristotle and that is associated with phrase structure grammars; the other constituent is the predicate. According to another tradition, i.e...

 or object

Object (grammar)

An object in grammar is part of a sentence, and often part of the predicate. It denotes somebody or something involved in the subject's "performance" of the verb. Basically, it is what or whom the verb is acting upon...

 by means of the verb. A predicative may be nominal or adjectival (and also adverbial). If the complement

Complement (linguistics)

In grammar the term complement is used with different meanings. The primary meaning is a word, phrase or clause that is necessary in a sentence to complete its meaning. We find complements that function as an argument and complements that exist within arguments.Both complements and modifiers add...

 after a linking verb is a noun or a pronoun, it is called a predicate nominative. If the complement after a linking verb is an adjective, it is called a predicate adjective.

He seems nice. (adjectival predicative of the subject)

Bob is a postman. (nominal predicative of the subject)

We painted the door white. (adjectival predicative of the object)

They elected him president. (nominal predicative of the object)

Predicatives may also be termed complements. Although sometimes object predicatives may be omitted leaving a well-formed sentence, in many instances they are essential to the meaning of the sentence:

That shrimp dish made him sick.

They called her a thief.

I consider him my friend.