Phonotactics of noun class disambiguation in Xhosa

Bantu languages are noted for their noun class systems. These noun classes tend to connect to semantic domains: e.g., humans are prototypically in classes 1 and 2. We present an experiment in which native speakers of Xhosa were shown singular nonce nouns with no semantic context, and were asked to provide the plural forms. These nouns were shown with the singular class prefix, which is ambiguous between class 5 and class 9. Historically, class 9 had a nasal prefix which triggered post-nasal alternations in stem-initial consonants. Since class 5 did not historically have a nasal, no such alternations occurred in class 5 nouns. Because of this, stems beginning with a segment that might have been the output of the historical post-nasal alternation may be interpreted as class 9, while stems beginning with segments that might have been inputs to these alternations may be interpreted as class 5. We show that speakers follow this pattern: roots beginning with post-nasal outputs were more likely to be assigned the plural corresponding to class 9 (i.e., class 10), and roots beginning with post-nasal inputs were more likely to be assigned to the plural corresponding to class 5 (i.e., class 6)