Relationship of form and function in grammaticalization - the case of modality

In this paper I discuss the issue of the relationship between form and function in grammaticalization, claiming that a correlation between formal and functional development only holds in the history of individual markers or constructions. If markers advance either formally or functionally, they will either advance or remain unchanged in the other aspect of their grammaticalization. Since there are also different entry points for lexical items - they may either be grammaticalized as a category low on grammaticalization scales or high - it is impossible to deduce and compare functional grammaticalization based on formal characteristics, and vice versa, even for markers of one grammatical category in one language. I also give an account of why functional grammaticalization is decisive and formal grammaticalization is rather epiphenomenal. This corresponds to the fact that formal degrammaticalization occurs much more easily. Functional grammaticalization is mainly understood in terms of an increase in speech-act orientation, and climbing in hierarchies of grammatical categories. I illustrate the discussion with examples from the grammatical categories of modality and evidentiality.