From a classical WP perspective, the practical benefits of word-based descriptions carry over to the use of words for “the systematic study of language” because the same properties that make words useful for practical descriptions, notably stable relations between forms and grammatical features, are also of theoretical value. The WP model does not exclude the possibility that ‘atomic’ units of grammatical meaning might be brought into correspondence with minimal units of form in some languages or patterns. However, WP approaches proceed from the assumption that a morphemic correspondence is certainly not normative, and frequently cannot be established in cases where a stable relation exists between words and grammatical properties.
Classical languages provide paradigm examples in which a relatively stable property-form relation at the word level cannot be projected downwards onto subword units. Latin rexistl on p. 35 above shows some of the types of many-many relations that arise between putative units of meaning and units of form. This case is by no means the most extreme example of its kind; classical Greek exhibits even more tangled patterns. To illustrate the range of relations that can hold between properties and forms, Matthews (1991) considers the classical Greek verb form elelykete ‘you had unfastened’ in Figure 3.1.
As Matthews observes, the realization of aspect and voice confounds any attempt to establish a biunique property-formative correspondence:
Figure 3.1 Exponence relations in Ancient Greek elelykete (Matthews 1991:173)
Figure 3.2 Many-to-many feature-form associations
But categories and formatives are in nothing like a one-to-one relation. That the word is Perfective is in part identified by the reduplication le- but also by the suffix -k-. At the same time, -k- is one of the formatives that help to identify the word as Active; another is-te which, however, also marks it as ‘2nd Plural’. (Matthews 1991:173)
More generally, Figure 3.2 shows how systematically properties and formatives are multiply associated. On one side, the properties past, perfective and active are realized by multiple exponents. On the other, all of the formatives other than the first pair, e- and -le-, realize two, and sometimes three, properties. There is nothing exceptional about elelykete within the inflectional system of Greek. On the contrary, the paradigm of lyo ‘to unfasten is treated as exemplary in standard grammars such as Goodwin (1894). Matthews (1991:174) notes that this paradigm does not show “any crucial irregularity” and “is in fact the first that generations of schoolchildren used to commit to memory”. Yet since the properties of elelykete are realized at multiple points within this form, individual features cannot be correlated with single formatives.