Sidewards without copying

A traditional movement step relates a single source position to a single c-commanding target position, and never moves an argument to another argument position. But head movement involves non-c-command relations, and control relates two argument positions that are not always in a c-command relation. Special mechanisms could be invoked for these things, but a different strategy slightly generalizes movement and enforces certain fundamental symmetries observed by all movements to block overgeneration. This paper defines a class of ‘sideward movement grammars’ (smmgs) with such symmetries, with example applications to adjunct control and head movement. These grammars allow copying, but the question of whether to copy is completely independent of the question of whether to allow sideward movement. Furthermore, since these grammars distinguish complement attachments from others, a simple CED-like constraint can block extractions from specifiers and adjuncts except in the exceptional circumstance of adjunct control. smmg definable languages are all pmcfg definable, and hence are efficiently recognizable.