The theory of Distributed Morphology
The theoretical approach of Distributed Morphology (DM) can be seen as one of the recent developments in Generative Theory. It was originally introduced in Halle & Marantz (1993) and later developed in Halle & Marantz (1994), Halle (1997), Marantz (1996, 1997), and subsequent work. The core idea of DM is the existence of a single generative component – namely, syntax – capable of building complex structures by combining smaller units in a systematic and hierarchical way. It represents, thus, a departure from lexicalist models, in which not only syntax, but also the lexicon, is able to employ generative mechanisms. Therefore, DM breaks the boundaries between sentence and word formation, which means it treats both sentences and words as being built by the same operations, implemented in the same component.
Under such an approach, the idea of a lexicon is greatly weakened, and DM postulates that many properties traditionally associated with it are distributed across the derivation. Specifically, the model makes use of three lists, each of them storing different types of information; those lists are accessed at specific moments of the derivation, when their information becomes necessary. Even if we cannot say that these ideas were new at the time (as the authors themselves acknowledge the inspiration in work by Lieber (1992), Aronoff (1992), and Beard (1991), to mention a few), the proposal of deriving words within syntax and combining it with post-syntactic phonological insertion and readjustments in a single grammar model is responsible for the novelty of Distributed Morphology.