Part A: Plural Units Denoting Amounts. In American English, a plural noun denoting a small unit by which a larger amount is measured generally takes a singular verb — e.g.: o “Five hours are [read ‘is’] enough time.” o “Fifteen minutes pass [read ‘passes’] more quickly than you might think.” Part B: “one and one (is) (are).” Both forms are correct. It’s possible to treat “one and one” as a single mathematical idea, so that the appropriate verb is “is.” Or it’s possible to treat the two “ones” separately — hence “are.” The same is true of multiplication: both “four times four is sixteen” and “four times four are sixteen” are correct. But the singular is much more common and more natural in modern usage. Part C: “thing after thing (is) (are).” This construction takes a singular verb — e.g.: o “Assault after assault on the M’Naghten Rules were [read ‘was’] beaten off until 1957.” H.L.A. Hart, “Changing Conceptions of Responsibility,” in Punishment and Responsibility 186, 191 (1968). o “Study after study has shown that in heterosexual couples, perpetrators are overwhelmingly men and victims are overwhelmingly women.” Kathleen Waits, “Domestic Violence,” in The Oxford Companion to American Law 222 (2002). Next: “more than one is”; *”more than one are.” For more information about the Language-Change Index click here. ——————– Quotation of the Day: “There is only one noun that can express your idea, only one verb that can put that idea in motion, and only one adjective that is the right epithet for that noun.” Flaubert (as quoted in Henry Bett, Some Secrets of Style 73 (1932)).