Morphology is in the eye of the beholder 

Conceptually, there are good reasons to assume that syntax and morphology form a single grammar module. Implementing this idea in a grammar model is problematic, however, because syntactic and morphological structures appear to require different kinds of rules. By distinguishing the morphosyntactic and phonological components of a structure, however, it becomes possible to describe syntactic and morphological structures in a unified model. An affix, for example, is syntactically no different from a free morph. The fact that it is a bound morpheme can be described as a fact about the phonological form of the affix by applying principles adopted from prosodic morphology. As it turns out, these principles can also be applied to syntactic structures, shedding some light onto phenomena that are otherwise difficult to account for syntactically.