Polysynthesis as a typological feature
Polysynthesis is characterized as a type of morphology, qualitatively different from inflectional morphology and from derivational morphology and redefined as productive noninflectional concatenation (PNC). Like syntax and unlike derivational morphology, PNC is fully productive, potentially recursive, necessarily concatenative, allows for ordering variability of some elements, and interacts with syntax. Unlike inflectional morphology and like syntax and derivational morphology, PNC can be category-changing. This postulated morphological feature is very prevalent in polysynthetic language families such as Eskimo (illustrated by Siberian Yupik), but not very prevalent in other language families often designated as polysynthetic, such as Athabascan (illustrated by Western Apache). This new characterization of polysynthesis has as an interesting consequence its existence, to a small degree, in Indo-European languages.