Functional changes and (meta-)linguistic evolution
In this contribution I assess some mainstream approaches to functional changes of grammatical expressions with a focus on two concepts – ‘(secondary) grammaticalization’ and ‘exaptation’. As to the former, I argue that the most influential definition of ‘grammaticalization’ by Kuryłowicz’s (1965) results from a terminological accident rather than from a systematic observation or analysis of linguistic changes. The consequence is that various heterogeneous properties are nowadays associated with one and the same concept. Generally, ‘grammaticalization’ as well as other functional changes discussed in the literature are defined by the status of an expression before and after a change, not by the process itself. On this basis, I will argue that ‘exaptation’ is a concept distinct from other mainstream notions of language change, provided that the context of ‘evolution’ as a principle of variation and change, out of which ‘exaptation’ was brought into linguistics, is taken seriously.