Abstract
Lexemes may take their inflections from more than one inflection class; this phenomenon, heteroclisis, is well represented in Serbo-Croat (BCMS). The data enable us to extend the typology of heteroclisis to include full heteroclisis (where the form in each cell of the lexeme’s paradigm belongs to two different inflection classes) and covert heteroclisis (where there is only external evidence of het- eroclisis, from agreement). Heteroclisis shows interesting interactions, and care must be taken to separate out the contributing phenomena. There can be an inter- action with partial deponency (morphological mismatch), and again the Serbo-Croat data are significant. Finally, a particularly complex example of heteroclisis shows a development towards becoming a more standard type of irregularity.