Locality Conditions and Phases in the theory of (wh-)
Research on locality is also an important line of inquiry in minimalist theorizing. According to the minimalist conception of locality, movement must be short; that is, it can operate only within a limited amount of structure. This shortness of movement was captured by the Subjacency Condition in terms of the limitation that a moved phrase can cross at most one cyclic node. This locality constraint on movement operations, which ‘‘in effect limits the ‘memory’ available to transformational rules’’ (OWM, 111), is now captured by the Phase Impenetrability Condition (Chomsky 2000, 2004a), which essentially states that only the edge (the specifier and head) of a phase (e.g., CP and vP) is accessible to syntactic operations in higher phases. This condition has the effect that a computational operation (e.g., the Agree relation, as part of the movement operation) cannot look too deeply inside a lower phase. According to this conception of locality, apparently unbounded movement results from successive-cyclic movement through the edges of different phases.
Another type of locality condition, based on Rizzi’s (1990) Relativized Minimality, is the Defective Intervention Constraint (Chomsky 2000, 2004a; see also Chomsky’s (1995) Minimal Link Condition). According to this principle, the probe (i.e., target of movement) always tries to enter into a matching relation (Agree) with the closest potential matching feature (i.e., dependencies must be satisfied in the smallest structure where they can be satisfied). An intervention effect (e.g., a violation of the Wh Island Constraint) is obtained if the probe a matches an inactive category b that is closer to a than a matching g. In such a configuration, an Agree relation between a and g is barred.
