Also called linking verb. Grammar. a verb, as be, seem, or look, that serves as a connecting link or establishes an identity between subject and complement.
The copula should always agree with the subject, not with the complement.
The same order of words is required by the copula with whatever kind of complement.
Each is a sequence of noun-copula-adjective-infinitive verb.
The copula is present if the superlative is used predicatively.
British Dictionary definitions for copula
copula
/ˈkɒpjʊlə/
noun (pl) -las, -lae (-ˌliː)
1.
a verb, such as be, seem, or taste, that is used merely to identify or link the subject with the complement of a sentence. Copulas may serve to link nouns (or pronouns), as in he became king, nouns (or pronouns) and adjectival complements, as in sugar tastes sweet, or nouns (or pronouns) and adverbial complements, as in John is in jail
2.
anything that serves as a link
3.
(logic) the often unexpressed link between the subject and predicate terms of a categorial proposition, as are in all men are mortal
Derived Forms
copular, adjective
Word Origin
C17: from Latin: bond, connection, from co- together + apere to fasten
Word Origin and History for copula
n.
linking verb, 1640s, from Latin copula "that which binds, rope, band, bond" (see copulate).
copula in Medicine
copula cop·u·la (kŏp'yə-lə) n. A narrow part connecting two structures.