Interaction between input frequency, transparency and productivity in acquisition of noun plural inflection in Danish

Acquisition of the Danish noun plural system is interesting in regard to testing hypotheses on input frequency effects: whereas English is characterized by having one default inflectional marker for a grammatical category (e.g. the plural suffix -s) and a minor number of exceptions to this default rule, Danish has several competing inflectional markers. Furthermore, there are important interactions between phonology and morphology in the Danish system (Basbøll et al. (2011)). In the present study we test theses on input frequency effects in a phonological perspective and explore the impact of phonetics on grammar. This will be done in three types of empirical data from monolingual Danish children: Naturalistic child directed speech and child speech from six children aged 0;10-3;11; Structured interviews with 80 children aged 3-9 years; Experimental data from 160 children aged 3-10 years. We present a scale with three degrees of transparency of the plural stem and of the plural suffix as well as a more differentiated scale of transparency of the Danish plural markers. We furthermore present a scale with three degrees of productivity, and analyze the relation between acquisition rate and degree of transparency as well as degree of productivity.