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Q. The editors at our institution disagree about whether the singular point or plural points should be used in the following phrase: “0.4 percentage point(s).” Can you be the decider, as our commander-in-chief would say, on this one?
A. Recently Chicago Tribune language writer Nathan Bierma made sense of this conundrum in a reply to a similar question. He quoted Bill Walsh of the Washington Post, who suggests that the trouble resides in thinking of the singular as one or less, whereas it’s more helpful to think of the singular as exactly one, neither more nor less. Walsh points out that we say “zero dollars,” not “zero dollar.” By this logic, you should write “0.4 percentage points.”