Q: I’m a New Yorker living in London. My housemate, who is British, refers to her scale in the plural. For a while I thought she was weighing herself on multiple scales, but that’s not the case—just one! What is the history behind this and what is the correct way to refer to the weighing instrument?
A: The thing you weigh yourself on in the bathroom can be called either the “scales” or the “scale.” The instrument is usually singular in the US and plural in the UK, though Americans often use the plural too.
For the full story, we have to go back to medieval times and to Old Norse, a language in which the word for a bowl was skal.
In the Middle Ages, according to the Oxford English Dictionary, this Old Norse word had several descendants in English, including “scale,” which once meant a cup or drinking bowl.
Weight entered the picture in the first half of the 15th century. That’s when “scale” began appearing in a new sense, says the OED: “the pan, or each of the pans, of a balance.”
The plural form, “scales,” was used soon after that to mean the weighing apparatus itself, according to OED citations.
In Oxford’s words, “scales” became a noun meaning “a weighing instrument; esp. one (often called a pair of scales) consisting of a beam which is pivoted at its middle and at either end of which a dish, pan, board, or slab is suspended.”
At about the same time, the OED says, the singular “scale” also came to mean the weighing instrument, though the singular form was often used figuratively, especially in the expression “to turn the scale” (to indicate an excess of weight on one side or the other).
Here’s an example of the singular from Shakespeare’s The Merchant of Venice (1600): “If the scale doe turne but in the estimation of a hayre [hair].”
As for use of the singular form today, The American Heritage Dictionary of the English Language (5th ed.) says one definition of “scale” is “an instrument or machine for weighing.” But AH adds that it’s often used in the plural too.
When used in the plural, the word requires a plural verb: “The scales aren’t weighing correctly … I’m sure of it!”
One final note. If you feel you need a drink after weighing yourself, here’s something to think about.
That old sense of “scale” as a cup or drinking bowl has long since died out and is no longer used by speakers of English (except in South Africa). But its Old Norse ancestor (skal) lives on in a familiar drinking toast, “Skoal!”
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