 In “Adverbs of Quantification” (1975a), Lewis notes several difficulties in translating sentences involving “usually”, “frequently”, “rarely” or related adverbs into first-order logic or some similar formal system. Lewis’s solution to the puzzles raised involves two formal advances. First, he treats the adverbs as unselective quantifiers, binding all free variables in their scope. The second advance concerns the if-clauses in sentences like Usually, if a team plays well, they win. It is difficult for various reasons to take the structure of this sentence to involve a quantifier over a compound sentence with a conditional connective. Lewis’s second advance is to say that these if-clauses are simply domain restrictors. The ‘if’ is no more a sentential connective than the ‘and’ in New York is between Boston and Washington. Instead, the if-clause restricts what things the quantifier denoted by ‘usually’ ranges over.