Some people, myself included, use the word
they as a singular gender-indeterminate pronoun, instead of defaulting to
he, or using
he/she, or expanding with
he or she, or other new-age pronouns like
zie, sie and hir.
From a usage note in the American Heritage dictionary:
The use of the third-person plural pronoun they to refer to a singular noun or pronoun is attested as early as 1300, and many admired writers have used they, them, themselves, and their to refer to singular nouns such as one, a person, an individual, and each.
W.M. Thackeray, for example, wrote in Vanity Fair in 1848, “A person can't help their birth,” and more recent writers such as George Bernard Shaw and Anne Morrow Lindbergh have also used this construction, in sentences such as “To do a person in means to kill them,” and “When you love someone you do not love them all the time.”
The practice is widespread and can be found in such mainstream publications as the Christian Science Monitor, Discover, and the Washington Post. The usage is so common in speech that it generally passes unnoticed.
However, despite the convenience of third-person plural forms as substitutes for generic he and for structurally awkward coordinate forms like his/her, many people avoid using they to refer to a singular antecedent out of respect for the traditional grammatical rule concerning pronoun agreement.
No one is willing to dispute this, are they?