The agreement of predicative adjectives refers to the phenomenon in which both the subject noun and its adjectival predicate[1] are marked for grammatical gender (class) and/or number. Prototypically, qualitative adjectives describing size, shape, and color are considered.[2]
Types:
NoAgr: Agreement is not possible, since neither grammatical gender (class) nor number exists in the language.
NoAdjAgr: Agreement exists[3], but it does not apply to adjectives, either adnominal (attributive) or predicative.
NoPredAdjAgr: Adnominal adjectives show agreement, while predicative adjectives do not.[4]
PredAdjAgr: Predicative adjectives show agreement for all grammatical categories that are marked for agreement on adnominal adjectives.
PredAdjNumAgr: Predicative adjectives show only number agreement.
PredAdjClassAgr: Predicative adjectives show only gender (class) agreement.
[1] The predicate may or may not include a copula.
[2] If these include any regular (non-lexical) exceptions, these should be noted in the commentary.
[3] Agreement refers to grammatical gender (class), number, and/or case. Non-adjectival forms of agreement may include adnominal demonstratives.
[4] The predicative adjective may appear in a morphologically similar form in terms of case or other categories, including grammatical gender (class) or number.