movement (n.)

A term often used within the framework of TRANSFORMATIONAL GRAMMAR to refer to a basic kind of transformational operation. Movement transformations have the effect of moving CONSTITUENTS (usually one at a time) from one part of a PHRASE-MARKER to another (the ‘landing site’), as in the formation of PASSIVE sentences. An alternative term is REORDERING or PERMUTATION. In some approaches this notion is broken down into the more basic operations of ADJUNCTION and DELETION. Two main types of movement rules have been used: WH-movement and NP-movement (as when such PASSIVE sentences as The cup was put on the table are said to DERIVE from – was put the cup on the table by NP-movement of the cup). Other such RULES have been proposed from time to time, such as DATIVE movement (to handle such alterations as X gave Y to Z and X gave Z Y) and though movement (to handle such sentences as good writer though she is . . . ); but the need for these has been disputed. The possibility that all movement rules may be reflexes of a single, universal rule (referred to as MOVE ALPHA) has also now been proposed. In later formulations, the category which has been moved leaves behind an EMPTY NODE, or TRACE: this approach is known as the ‘trace theory of movement rules’. A moved constituent and its CO-INDEXED trace form a movement chain. In the minimalist programme, move is a basic operation which moves elements about in the process of TREE construction. Movement is constrained in various ways. Only the shortest movements of an element are acceptable (SHORTEST MOVE) into the nearest relevant position (the minimal link condition). Movements should be delayed until absolutely necessary (PROCRASTINATE). And movements must satisfy the requirements of the moved element (GREED). In earlier formulations of the programme, move existed alongside MERGE; later formulations regard move as a subtype of merge. In this approach, move is called ‘internal merge’ and merge is called ‘external merge’.