Alignment and weight in the Tigrinya verb stem

In the Type A Imperfective paradigm of Tigrinya (Ethio-Semitic), unsuffixed verbs have a geminate medial consonant (yÁ-s√bbÁr), while verbs with a subject or object suffix do not have gemination (yÁ-s√br-u). This alternation has been analyzed from various points of view. A fundamental question is whether the more basic stem-form has gemination (Berhane 1991, Rose 1993) or not (Harris 1987, Denais 1990). Another important question is why the ungeminated form occurs with suffixes, rather than the other way around: Hayward (1987) stipulates that gemination occurs in unsuffixed forms, while Berhane (1991) posits special floating suffixes used in the Imperfective. Using the constraint-based framework of Optimality Theory (Prince and Smolensky 1993), I argue that the ungeminated form (yÁ-s√br-u) is more basic, but that the best analysis does not make explicit reference to suffixes at all. Rather, with appropriate constraints on the overall shape of the Imperfective verb stem, the gemination alternation is an automatic consequence of the absence of a suffix.