(1) A term often used within the framework of transformational grammar to refer to a basic kind of transformational operation. Reordering transformations have the effect of moving constituents from one part of a phrase-marker to another, as in the formation of passive sentences, or the placement of negatives and affixes. An alternative term is movement or permutation. In government-binding theory, reordering involves either adjunction or substitution.

(2) Reordering is also used in transformational analysis of linguistic change, referring to differences in the historical sequence of rules which must be postulated in order to explain the divergences between dialects, forms, etc. The matter has been discussed mainly with reference to phonology, and various types of rule-ordering relationships have been suggested.