Adjective phrases in English grammar are phrases in which an adjective functions as the head of the phrase. Adjective phrases perform adjectival grammatical functions.
Adjective phrase is a grammatical form.
The four grammatical functions performed by adjective phrases are noun phrase modifier, subject complement, object complement, and appositive.
The four grammatical forms that may appear in adjective phrases are the adverb phrase, prepositional phrase, verb phrase, and noun clause.
Brinton, Laurel J. & Donna M. Brinton. 2010. The linguistic structure of Modern English, 2nd edn. Amsterdam: John Benjamins Publishing Company.
Hopper, Paul J. 1999. A short course in grammar. New York: W. W. Norton & Company.
Huddleston, Rodney. 1984. Introduction to the grammar of English. Cambridge: Cambridge University Press.