Excuse me: the exact concept or definition of English predicative.

Predicates are used to explain features, states, etc. Meaning of subject and supplementary subject. So it is also called subject complement. Predicates are usually used after conjunctions. Besides be, conjunctions include becoming, seeing, turning, going, appearing, feeling, sound and smell. Can be used as predicative: adjectives, pronouns, nouns, participles, gerunds, numerals, prepositional phrases or adverbs and clauses: for example:

We are students.

He is very clever.