Seth Cable gave a colloquium talk at MIT last Friday, February 19. The title of his talk was: “The Curious Implicatures of Optional Past Tense in Tlingit (and other languages).” An abstract follows.
Some languages appear to have a morpheme that combines the meaning of past tense with a variety of additional implications, the nature of which depend upon the aspectual marking of the verb. For non-perfective verbs (imperfective, habitual, future,etc.), the additional implication is that the event/state in question fails to extend into the present. For perfective verbs, however, the additional implication is either that (i) the result state of the event fails to extend into the present, or (ii) some natural, expected consequence of the event failed to occur. Importantly, unlike the superficially similar ‘cessation implicatures’ of past tense in languages like English, these aforementioned implications cannot be directly cancelled. Consequently, prior authors have viewed these additional inferences as semantic in nature, as being encoded directly in the lexical semantics of the morpheme (Leer 1991; Copley 2005; Plungian & van der Auwera 2006). Under this view, the morphemes in question express a special category of tense, one that has been labeled ‘discontinuous past’ by Plungian & van der Auwera (2006).
Through in-depth investigation of one such ‘discontinuous past’ marker in the Tlingit language, I argue that – to the contrary – the special inferences of these morphemes are not semantic, and are instead defeasible pragmatic inferences. Consequently, putative instances of ‘discontinuous past’ are in their semantics simply past tenses. I provide a formalized analysis of the pragmatic inferences associated with these past tenses, whereby they ultimately follow from (i) the optionality of the tense markers in question, and (ii) a special principle relating to the inherent topicality of the utterance time. The empirical and analytic results align well with a restrictive theory of cross-linguistic variation in tense semantics, one where the only tense categories across language are Past, Non-Future, and (maybe) Present (Cable 2013).