On tense and aspect

I propose an output constraint that filters syntactic structures at the interface between syntax and semantics. This constraint requires the situation the sentence describes to be construed as located at a point of time included within an interval of time directly or indirectly defined by the speech act. A universal syntactic T(ense)-Chain places a situation at a point of time, linking the Reference time associated with the Complementizer node to the Event time associated with the Tense node. In Logical Form, the situation which vP describes is predicated of the point of time which T denotes.It is less straightforward, however, to place an event within an interval of time. To do this, the event time morpheme in T must merge with an aspect morpheme. I propose that aspect has nothing to do with the internal structure of events, as is often assumed. Rather, aspect pluralizes the point of time T denotes, deriving a series of points, or interval, of time.In Ancient or Modern Greek, both tense and aspect are realised as grammatical morphemes affixed to the verb. But other languages lack either perfective or imperfective aspect morphemes, or both. English, for example, lacks imperfective aspect while French lacks perfective aspect. A grammar with defective aspect must develop compensatory mechanisms which allow it to satisfy the output constraint on temporal interpretation mentioned above. English grammaticalized the possessive lexical verb HAVE, deriving an imperfective auxiliary verb. French and other languages raise a perfect participle from a lower syntactic domain to the higher, tense, domain where it functions as a perfective temporal form defining a bounded time interval in T.I argue that if the same verb can be construed as either lexical or grammatical, like English HAVE, or the same grammatical suffix can be construed as either an aktionsart morpheme which bounds an event or as an aspect morpheme which bounds a tense interval, like the French participial suffix, it is because the sentence structure is divided into two syntactic domains, vP and TP/CP, associated with distinct semantic construals.