Degrammaticalization and obsolescent morphology

Recent work in grammaticalization has highlighted cases where former inflectional affixes have gained independence on an unexpected path towards clitic or full-word status. Such cases challenge the hypothesized unidirectionality of grammaticalization at the formal level (word > clitic > affix). This article examines such developments, citing new evidence from the development of the person–number inflection of the conditional auxiliary in Slavonic. In some varieties, this comes to be identified with an existing clitic, the present tense of the perfect auxiliary ‘be’. This development is reminiscent of other cases where obsolescent morphology is reassigned to productive functions and which can best be treated as instances of exaptation–adaptation, a process which lacks directionality and frequently leads to counterdirectional change.