On the interpretability of tense on D and its consequences for case theory

Pesetsky and Torrego (Pesetsky, D., Torrego, E., 2001. T-to-C movement: causes and consequences. In: Kenstowicz, M. (Ed.), Ken Hale: A Life in Language. MIT Press, Cambridge, MA) argue that in English T on D is [-interpretable] and this has the effect of structural case assignment. I propose that in Halkomelem Salish T on D is [+interpretable]. This proposal accounts for several properties of Halkomelem: i) nouns can bear tense marking, which manipulates the temporal interpretation of nouns, ii) there is no TP and iii) there is no nominative case. The value of interpretability of a given feature can thus be viewed as an important locus of parametrization.