Agreement
AGREEMENT is a general term used to describe a situation in which the grammatical features of a noun or noun phrase determine the morphological shape of a word that is syntactically related to the Nor NP in some way (Lehmann1988;Haspelmath2002:65ff).This syntactic relationship may be anaphoric, as when a pronoun agrees with its antecedent, or it may involve a relation between a head and its dependent, as when a verb agrees with its subject or object.1
Other examples of heads that agree with dependent NPs include possessed nouns, which in some languages agree with their possessor NP, and prepositions, which in a few languages agree with their “object” NP. The features of the NP which may be reflected in the form of the agreeing head are gender, number, and person.
Within a noun phrase, the reverse pattern can occur: one or more dependents within the NP may agree with their head noun (N). These dependents typically include adjectives, determiners, and/or possessive pronouns. Some linguists use the term CONCORD to refer to this kind of agreement. The features of the head noun which may be reflected in the agreeing dependent forms are gender, number, and case.
1. See Nichols (1986) for a discussion of “head-marked” vs. “dependent-marked” agreement.