Q. Dear CMOS! I have a grammar question that has thrown our small department into a tizzy. In a sentence like “There are an even number of kittens on the veranda,” we are evenly split (pun intended!) as to whether “There are” is correct since there are a plural number of kittens or “There is” is correct because the number is (see? “is”) even. We’ve checked Garner’s entry for “number of,” which seems to throw down in favor of “there are,” but those of us in the “there is” contingent aren’t convinced. Any light the CMOS team can shed on this?
A. The expression “a number of” is an idiomatic phrase that means “some” or “several,” which is why a plural verb would normally be expected after “a number of kittens” used by itself: A number of kittens [or Some kittens] are on the veranda—or, if you invert the sentence, There are a number of kittens [or some kittens] on the veranda.
But if you change a to the, the idiom goes away, and the focus switches to the word number itself, making a singular verb the correct choice: The number of kittens on the veranda is huge. If you then invert that, however, you’re back to the plural: A huge number of kittens are on the veranda. So far, we’re mostly in line with Garner’s Modern English Usage, 5th ed. (2022), under “number of.”
But huge in that inverted example keeps things idiomatically plural: A huge number of kittens simply means lots of kittens, an expression that requires a plural verb. An even number, by contrast, means just what it says: a number that’s even instead of odd. And though it isn’t one of the examples featured in Garner, an even number doesn’t seem to have an obvious plural idiomatic equivalent like some or lots that could replace it; therefore, a singular verb is arguably the better choice: There is an even number of kittens on the veranda.
In other words, the number of kittens on the veranda is even (🐈🐈🐈🐈) rather than odd (🐈🐈🐈), an observation that puts the number ahead of the kittens. Nothing is certain when it comes to kittens, but that’s our take.