copulative vs copula

copulative and copula both are nouns.

Word	Noun	Adjective	Verb	Adverb
copulative	Yes	Yes	No	No
copula	Yes	No	No	No

As nouns, copulative and copula are synonyms defined as:

copulative and copula: an equating verb (such as `be' or `become') that links the subject with the complement of a sentence

Other synonyms of copulative include linking verb.

copulative (noun)	copula (noun)
an equating verb (such as `be' or `become') that links the subject with the complement of a sentence	an equating verb (such as `be' or `become') that links the subject with the complement of a sentence

copulative (adjective)	copula (adjective)
syntactically connecting sentences or elements of a sentence