SUMMARY
The paper examines the "predictability criterion", a classificatory tool which is used in selecting affixed word forms for dictionary entries. It focuses on the criterion as it has been used by the African Languages Lexical (ALLEX) Project for selecting extended verbs to enter as headwords in the Project's first monolingual Shona dictionary <i>Duramazwi ReChiShona</i>. The article also examines the status of Shona verbal extensions in terms of their semantic input to the verb stems they are attached to. The paper was originally motivated by two observations: (a) that predictability seems to be a matter of degree; and (b) that the predictability criterion tended to be used inconsistently in the selection of extended verbs and senses for <i>Duramazwi ReChiShona</i>. An analysis of 412 productively extended verbs that were entered as headwords in <i>Duramazwi ReChiShona</i> shows that verbal extensions can bring both predictable and unpredictable senses to the verb stems they are attached to. The paper demonstrates that for an effective use of the predictability criterion for selecting extended verbs for Shona dictionaries, there is need for the lexicographer to have an in-depth understanding of the kinds of semantic movements that are caused when verb stems are extended. It shows the need to view verbal extensions in Shona as derivational morphemes, not inflectional morphemes as some earlier scholars have concluded.