condition (n.)

A term used in LINGUISTICS to refer to any factors which, it might be argued, need to be taken into account in evaluating a theory, a GRAMMAR, or an individual analysis, e.g. such conditions as external ADEQUACY, GENERALITY, SIMPLICITY. More specifically, it refers to any criterion which must be met before a particular analysis may be carried out. In SYSTEMIC grammar, for example, the ENTRY conditions specify the structural criteria which must be satisfied in order for a particular grammatical system to become operative. In TRANSFORMATIONAL grammar, the STRUCTURAL DESCRIPTION which provides the input to a transformational RULE specifies the conditions which must be met before the rule can operate. Later, in this theory, the term was used to refer to the factors which constrain the application of transformations, in such contexts as MOVEMENT rules. For example, one condition states that a moved CONSTITUENT can only be substituted for an EMPTY category; another, that a moved constituent leaves behind a CO-INDEXED TRACE of itself. The ‘ISLAND condition’ asserts that SUBJECTS and ADJUNCTS, but not COMPLEMENTS, are islands; i.e., constituents can be extracted out of complement phrases, but not out of subject/adjunct phrases. Since the late 1970s, conditions on transformations have largely been replaced by conditions on various levels of REPRESENTATION, e.g. BINDING THEORY (a set of conditions on surface structures and/or logical form) replaced several conditions on rules of grammar proposed during the 1970s.