Let’s say you just backed up your computer, and you get a message that says, “Your data is now safe.”

Super. But wait. Should that be “Your data are now safe”?

‘Data’: The Latin Plural of ‘Datum”

The word “data” comes to English from Latin, in which “datum” is the singular and “data” is the plural. If you’re sticking with that history, it should be “Your data are now safe.” “Data.” Plural.

‘Data’: The English Singular Meaning ‘Information’

But I bet that sounds weird to a lot of you because since the 1940s, people have been using “data” as a singular noun more and more often, especially in general writing.

It’s not the first plural Latin noun to decide that it might be happier as a singular either. Consider “agenda.” It also comes from Latin and has a singular form: “agendum.” But if you ask your coworkers about the agendum for Monday’s meeting, you’re likely to get weird looks. Almost everybody thinks of “agenda” as singular—so much so that dictionary.com includes “agendas” as a possible plural of “agenda.” In fact, the Corpus of Contemporary American English includes almost 2,500 examples of “agendas,” including talk of “government agendas” in the “Texas Law Review," “competing agendas” in the “Chicago Sun-Times,” and “global agendas” in “The Lancet.”

“Data” hasn’t made as much of a complete shift to the singular as “agenda” has though.

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