Feast and Famine: Confronting Overabundance and Defectivity in Language

Every day, as we use language, we unconsciously select forms of words that feel "right" for what we want to say. Occasionally, however, multiple forms may compete for a slot, such as the participle of 'prove' (have proved? have proven?); here, users find both forms adequate, although each of us might only use one of them. Elsewhere, we lack a suitable form where one is expected: we may baulk at forming the past tense of the verb 'troubleshoot', where we have a "slot" (past tense of a particular word) but no form that can adequately fill it (troubleshot? troubleshooted?). These examples of "feast" (multiple forms) and "famine" (no forms) show that selecting the "right" word form is not a process of mechanically mapping from function to form; instead, users weigh and select forms from a basket of those available to us, sometimes keeping around more forms than necessary and sometimes failing to find a form that works for us. Linguists term the first sort of mismatch 'overabundance', and the second sort 'defectivity'. These mismatches cause difficulty for traditional linguistic theories, which assume that each form we use fulfils one function, and that each function can be fulfilled by one form. For the most part, this is true: if adult native speakers need a past tense of the verb 'choose', they head unerringly for 'chose', never *choosed or *chost. This results in an assumption that inflection (form-selection) is automatic, judgement-free, and innate rather than learned. Language handbooks then write this assumption into practice, describing forms and features very differently from how a speaker might actually use them. Defectivity and overabundance have traditionally been treated as separate phenomena, arising in different circumstances that explain their divergent outcomes. Our project highlights the commonalities in these circumstances - it is the outcomes (multiple forms or none) that mark them as distinct. Using data from morphologically complex languages - Czech, Croatian, Estonian and a further language chosen by the PDRA - we explore a fundamental question: which factors push users and models of use down one or the other path? We converge on an answer by considering multiple perspectives: - The Czech National Corpus Institute will use CORPUS DATA, particularly from more "naturalistic" subtitle corpora, to uncover new methods for identifying competition (overabundance) and gaps (defectivity) in the "real world" of texts: their methods (collocation, keymorph analysis, frequency distribution) will be refined, elaborated and tested on project languages via experimental and computational methods. - Sheffield will use EXPERIMENTAL DATA from adult native speakers to examine language users' reactions to overabundance and defectivity by confronting them in similarly structured tests - which show in what way our reactions are (or are not) measurably different to these two slot types. These data will also help assess aspects of SOCIOLINGUISTIC VARIATION, such as education and reading skills. - York will test, refine and develop COMPUTATIONAL MODELS OF INFLECTIONAL MORPHOLOGY to see how they handle and predict overabundant and defective slots. - Zagreb and York will collect LANGUAGE ACQUISITION DATA in naturalistic and experimental settings to illuminate how learners make sense of "messy" data such as those found in overabundant and defective slots. Overabundance and defectivity will be examined as potentially differing, temporary responses to structures of uncertain predictability. As an integral part of the project, staff in Zagreb and Prague will translate our findings into GUIDELINES for language users, feeding directly into public-facing language resources such as online dictionaries and handbooks of the target languages. Instead of seeing idealised systems that linguists project for them, as at present, speakers will get information on how their language is used in a clear and user-friendly format.