2015 was a big year for the little pronoun they and its slide into use as a singular pronoun.
First, in December, the Washington Post admitted the singular they into its style guide, saying it is fine for Post writers to use they as a singular pronoun for transgender people and to avoid awkward sentences. Then last week, hundreds of linguists at the American Dialect Society annual meeting voted for the singular they as the 2015 word of the year.