 It appears, then, that we have two different languages. In the first, verbs are tenseless but dated. In the second, verbs are tensed but undated. Do we need two languages? In the language with dates, we can measure that interval between two events, and compare it with the interval between two other events. In a system of moving objects, we can partially order the dates via the Special Theory of Relativity. Why bother with the tensed system at all?