We have described rich systems of morphology in sign languages – specifically, inflectional morphology, the type that is related to the use of words with other words in sentences. But that is not the only kind of morphology that exists in sign languages. The morphology of lexeme formation – derivational morphology – is also to be found in languages of signs. As in the inflectional component, much of the derivational morphology of sign languages is templatic.

Templatic derivational morphology in sign languages

The clearest earmark of derivational morphology is a change in lexical category (part of speech), and one of the earliest studies of derivational morphology in ASL concerned the relation between certain pairs of nouns and verbs (Supalla and Newport 1978). As we show in Section 4.1.1, this is an example of the typical templatic derivational morphology found in ASL and other sign languages. This subsection also discusses several other templatic derivational processes observed in ASL. Allomorphy is observed in ASL as well. The degree of linguistic abstractness inherent in allomorphy is highlighted by a particular ASL allomorphic alternation that is shown to extend to different homophonic morphemes. The chapter concludes with a discussion of non-manual morphemes. In these morphemes expressed on the face, we find a modality-specific type of simultaneous morphology, but one that is nevertheless strictly constrained.