 It is generally agreed nowadays that, contra Carlson’s earliest work, there is a two-place operator, usually termed Gen, which functions as an adverb of quantification (Lewis 1975). Adverbs of quantification include “usually”, “generally”, “typically”, “always”, “sometimes”, and so on. They function to relate one set of conditions containing at least one free variable to another set. Adverbs of quantification are, in Lewis’s sense, unselective, meaning that they bind any number of free variables in the sentence, be they objects, events, or locations. Consider, for example, the following sentence: