Each student was talking about how hard their homework was.
As natural as it may feel to pop out with sentences like the one above, we know it’s wrong. We know that they and their are plural, so they can’t possibly refer back to each student, which is singular. But let me assure you that the rule has never made any more sense than throwing rice at a bride. It’s got to go.
The author of the fourteenth-century romance Amadas had no problem with Iche mon in thayre degree for Each man in their degree. But if something that antique seems inapplicable because maybe medievals weren’t bright enough to keep pronouns in their cages, what about the Bard in The Comedy of Errors: “There’s not a man I meet but doth salute me / As if I were their well-acquainted friend.”
Examples are endless, such as Thackeray in Vanity Fair writing, “A person can’t help their birth.” So why is the notion that they or their is plural as unquestionable as the law of gravity? It traces back not to some self-standing “canon” or scientific principle, but to an English grammarian who, as far as anybody can tell, just made it up in the 1740s that he should refer to both boys and girls. (For what it’s worth, this grammarian was a woman, named Ann Fisher.) The notion was then passed down through the centuries, such that Strunk & White taught us not to use it. Apparently William Strunk had a certain classroom charisma, but are we really to heed his aesthetic sensibilities over Shakespeare’s or Thackeray’s?
Doing so creates little of worth. Experiments prove what we would suspect of using he as a generic: When people are asked to read a sentence with a supposedly gender-neutral he, they almost always assume that a man is being referred to. One alternative, putting women last in a he or she formulation, is sexist—as is, by definition, she or he. Switching between he and she looks studied, he / she is unpronounceable, and compromise neologisms like hesh never catch on.
Meanwhile, languages like German have switch-hitting pronouns like sie for she and they, and no one bats an eye. Any editor wanting to connect modern English to its roots should know that they have a responsibility to allow sentences like, well, this one.