In January, the American Dialect Society announced that the word of the year is “they” but as a singular pronoun rather than its historic plural usage. As all elementary English students know, they is a plural pronoun in writing and is cause for a lot of red marks on graded papers.
However, English speakers have been using singular they in speech for a long time – with no issues in understanding. It is still very frowned upon in proper writing but some newspapers and magazines had already changed their style guides to reflect this 21st century use. Partly this has to do with just codifying the way we are already using language but the other part is that English has no gender neutral singular pronoun for the third person and singular they addresses that lack.