Buckler, H. 1, 2 & Fikkert, P. 1
1 Radboud University Nijmegen
2 International Max Planck Research School for Language Sciences
Preverbal infants do not perceive ham and hamlet as related words (Jusczyk et al., 1999) but they can use the distribution and frequency of inflectional affixes to posit links between stems and inflected forms (Marquis & Shi, 2012). Affixation often involves more than just segment concatenation and may trigger alternations within morphological paradigms. Intraparadigmatic voicing alternations occur in Dutch and German due to final devoicing. This phonotactic constraint prohibits voiced obstruents word-finally, however, when followed by a vowel-initial suffix voicing is permitted, e.g. Dutch be[t]-be[dd]en 'bed(s)'. This study, using the head-turn preference procedure, investigated whether 9-month-olds can incorporate their morphological and phonotactic knowledge and assign bare roots and inflected forms to the same lexical entry when there is suffixation and voicing alternation. Testing Dutch and German infants enables us to address the contribution of language-specific factors on the acquisition of voicing alternations, e.g. functional load of voicing and frequency of alternations. Infants were familiarised on passages containing monosyllabic, singular nouns and tested on lists of bisyllabic, plural forms. Experiment 1 involved suffixation only (dot-dotten). Both Dutch and German infants succeeded in relating forms to the same lexical entry; orientation times to familiar and novel items differed significantly. This early sensitivity to inflectional affixation has not previously been attested in these languages, and not at this young age. Experiment 2 introduced voicing alternations as well as suffixation (mut-mudden). Here neither group perceived links between singular-plural pairs when there was a voicing alternation present. Despite differences in frequency of alternations and the importance of the voicing contrast in the language being acquired (both of which may aid acquisition) 9-month-olds are not yet aware that a morpheme may have more than one surface form, seemingly treating [t] and [d] as contrastive phonemes that map to separate lexical entries, even when this is incorrect.