Agreement

Agreement is a phenomenon in natural language in which the form of one word or morpheme covaries with the form of another word or phrase in the sentence. For example, in the English sentence John walks Fido every morning, the form of “walks” is conditioned by features of the subject, “John.” This can be seen by replacing “John” with an element whose relevant features are different, as in We walk Fido every morning, which results in a change in the form of “walks” to “walk” (or alternatively, a change of “-s” to an empty morpheme, Ø). Agreement is perhaps the quintessential morphosyntactic phenomenon, since it involves the morphological expression of a relation that most researchers take to be a syntactic one (though not entirely without dissent; see Morphologically Oriented Approaches). In contemporary linguistic literature, the term agreement is (somewhat unfortunately) used to refer alternately to the phenomenon itself, and to the hypothesized grammatical mechanism that gives rise to it. Unless otherwise noted, the term will be used here in the theory-neutral, descriptive sense only. Another point of terminological variability concerns the identity of the grammatical elements that enter into agreement. Canonically, the term is used to describe morphological covariance between some verbal element in a clause (typically, the bearer of tense/mood/aspect morphology) and a nominal argument in the same clause; but the term has also been used to describe many other pairings of covarying elements (e.g., nominals and their adjectival modifiers, nouns and their possessors, pre-/postpositions and their complements, etc.; and more recently, sequence-of-tense effects, pronouns and their antecedents, and even the relationship between multiple negative elements in a single clause; see Recruiting Agreement as an Explanation of Other Phenomena). Agreement is cross-linguistically very common; at the same time, languages of the world can differ quite dramatically in the amount of agreement morphology they exhibit. On one end of the scale, a language like Mandarin has nary any canonical agreement to speak of; while languages like Abkhaz, Basque, Icelandic, and others exhibit robust patterns of agreement between verbs and their arguments, nouns and their modifiers, and so forth.