Feature Constraint ( Concept )

      |_ Abstract
            |_ Linguistic Data Structure
                  |_ Feature Constraint


A term used in linguistics, and especially in generative grammar, to refer to a condition which restricts the application of a rule, to ensure that the sentences generated are well formed. For example, in generative phonology, a distinction can be made between ‘simulatenous’ and ‘sequential’ constraints: the former states the restrictions on the simulataneous occurrence of features, e.g. a segment cannot be at once [+high] and [+low]; the latter states the restrictions on sequences of features, e.g. whether a language permits consonant clusters. In generative syntax there are also several constraints which have to be imposed in order to prevent the derivation of ill formed phrase-markers, e.g. constraints on the ordering of rules. The notion of constraints takes on a different direction in optimality theory, where it is the principle explanatory device. Here, constraints are ways of characterizing language universals. Each language has its own ranking of constraints (e.g. which determine morpheme position or syllable structure), and differences between these rankings result in the variations observed between languages. [Crystal 2003: 101]

Usage Notes


data Structure Relation Thing     This subsumes all structuring relations used for LinguisticDataStructures. As a naming convention to distinguish relations in data structure from other relations, all names of dataStructuringRelations begin with 'has-'.

User Submitted Issues