Segmental noun/verb phonotactic differences are productive too

Not all statistical patterns in a speaker’s lexicon are acquired productively , and it has been proposed that distinguishing between those patterns that are productive and those that are not serves as a source of evidence for the existence of learning biases in the grammar (Becker et al. 2011). A cross-linguistic survey of categorical noun/verb phonotactic differences finds that most of them involve prosodic patterns, such as stress or tone, not segmental ones—but does this typological asymmetry actually result from a learning bias against segmental noun/verb differences? English provides a testing ground for this question, as the lexicon has statistical differences between noun and verb phonotactics involving not only stress, a prosodic property, but also fricative voicing and vowel backness, which are segmental properties. A nonce-word noun/verb categorization experiment finds that adult English speakers apply all three patterns productively, even the segmental ones. Moreover, evidence for productive knowledge is found even when the effect of existing morphological alternations (such as the stress alternation seen in permit N/ permit V) is controlled for. These results contribute to a growing body of evidence that gaps in language typology do not necessarily correspond to patterns that are unlearnable.