 Angelika Kratzer’s work on conditionals has been very influential in linguistics, and also in philosophy. Her articles have appeared, reworked, as a book, Modals and Conditionals (2012). Kratzer’s inspiration comes from a paper by David Lewis, “Adverbs of Quantification” (1975). Lewis’s paper is about the analysis of sentences containing adverbs such as always, never, usually, often, seldom …, sentences such as “The fog usually lifts before noon here” and “Caesar seldom awoke before dawn”. After considering and rejecting some alternatives, Lewis introduces “restriction by if-clauses”: he proposes that there is a use of if-clauses whose function is to restrict the range of cases to which the operator or quantifier applies. First paraphrase the sentences: “Usually if there is fog here, it lifts before noon.” “Seldom if Caesar awoke, it was before dawn.” (Lewis’s target sentences do not have “if” in their surface structure, but they could have had: the theory also applies to sentences like “Usually, if Mary visits, she brings her dog”.) The “if” restricts the “usually” to the occurrences of fog here, or of Mary’s visits, and the “seldom” to Caesar’s awakenings. These sentences are not to be construed as applying an adverb to a conditional proposition. The adverb applies to the main clause, its scope restricted by the if-clause. Thus Lewis: 