The parameters
Grammatical change has been described in terms of a wide variety of different models. In works on grammaticalization, the emphasis has been on two aspects of change. One aspect concerns semantics, in that this process is primarily one that leads from less grammaticalized to more grammatical meanings. The second aspect concerns pragmatics, and in particular the role of the frequency of use and context. In the handbook-like treatments mentioned above, attempts are made to reconcile these two aspects in some way or other. The methodology employed here (see also Heine and Kuteva 2002a, 2005) rests on the assumption that grammaticalization is based on the interaction of pragmatic, semantic, morphosyntactic, and phonetic factors. There is a wide range of criteria that have been proposed (see e.g. Lehmann 1982; Heine, Claudi, and Hünnemeyer 1991; Hopper and Traugott 2003; Bybee, Perkins, and Pagliuca 1994); in our model it is the four parameters listed in (13). A wide range of alternative criteria have been proposed, such as syntacticization, morphologization, obligatoriWcation,1 subjectification, etc. We argue that they can be accounted for essentially with reference to these four parameters. Henceforth we will rely on these parameters, using them as a tool for identifying and describing instances of grammaticalization.
(13) Parameters of grammaticalization2
a. extension, i.e. the rise of new grammatical meanings when linguistic expressions are extended to new contexts (context-induced reinterpretation)
b. desemanticization (or ‘‘semantic bleaching’’), i.e. loss (or generalization) in meaning content
c. decategorialization, i.e. loss in morphosyntactic properties characteristic of lexical or other less grammaticalized forms
d. erosion (‘‘phonetic reduction’’), i.e. loss in phonetic substance.
Each of these parameters concerns a different aspect of language structure or language use: (13a) is pragmatic in nature, (13b) relates to semantics, (13c) to morphosyntax, and (13d) to phonetics. Except for (13a), these parameters involve a loss in properties. But the process cannot be reduced to one of structural ‘‘degeneration’’; there are also gains. In the same way as linguistic items undergoing grammaticalization lose semantic, morphosyntactic, and phonetic substance, they also gain properties characteristic of their uses in new contexts—to the extent that in some cases their meaning and syntactic functions may show little resemblance to their original use.
The ordering of these parameters reflects the diachronic sequence in which they typically apply: Grammaticalization tends to begin with extension, which triggers desemanticization, and subsequently decategorialization and erosion. Erosion is the last parameter to be involved; as we will see below, erosion is not (or not yet) a relevant parameter.
1 Some students of this paradigm of linguistics argue that obligatorification, whereby the use of linguistic structures becomes increasingly more obligatory in the process of grammaticalization, should be taken as a definitional property of this process. As important as obligatorification is (see Lehmann 1982), it is neither a sine qua non for grammaticalization to take place, nor is it restricted to this process, occurring also in other kinds of linguistic change, such as lexicalization. Within the present framework, obligatorification—as far as it relates to grammaticalization—is a predictable by-product of decategorialization.
2 Our use of the term ‘‘parameter’’ must not be confused with that found in some formal models of linguistics. For an alternative account of grammaticalization within a Chomskyan Minimalist framework, see van Gelderen (2004), where this process is described in terms of economy principles, entailing in particular a syntactic shift from specifier to head, e.g. from main verb to auxiliary, from demonstrative to definite article, etc.
