No heads turn when someone says, “Everyone is bringing their own lunch.”
Except … it should be, grammatically speaking, “Everyone is bringing his own lunch.”
This brings up the whole question of our ubiquitous use of they and their as singular pronouns and possessives. As I noted, no heads turn when people use the plural to modify a singular antecedent.
I mention this after reading an interesting article in the New York Times, “Toppling the Grammar Patriarchy,” which describes French teachers’ rebellion over defaulting to masculine forms even when the subject includes both male and female.
Here’s an example by author Carmel McCoubrey: [“I]f you wrote a sentence about attractive (beaux) étudiants and attractive (belles) étudiantes, the adjective used to describe them had to be masculine, too: “Les étudiants et les étudiantes sont beaux.”
Similarly in English, a singular antecedent requires a masculine pronoun, as shown in sentence two above. If you switch to a plural antecedent, you solve the whole problem; for instance: “All participants are bringing their own lunch.”
Here’s how McCoubrey’s employer embraces the issue:
Yet The Times’s stylebook is adamant: ‘Anybody, anyone, everybody, everyone, no one, someone, all require he or she (never they) on further reference: Has anybody lost his ticket?’ It goes on to say, ‘As a last resort, the awkward his or her is tolerable; a plural pronoun with a singular antecedent is not.’
McCoubrey concludes: “[S]ometimes I stare at a sentence and long for the day the “singular they” (which, Merriam-Webster says, has been used since the 1300s) is acceptable.” everywhere.