Singular they

Singular they, along with its inflected or derivative forms, them, their, theirs, and themselves (also themself and theirself), is a gender-neutral third-person pronoun derived from plural they. It typically occurs with an indeterminate antecedent, to refer to an unknown person, or to refer to every person of some group, in sentences such as:

This use of singular they had emerged by the 14th century, about a century after the plural they.^[4][5][2] Singular they has been criticized since the mid-18th century by prescriptive commentators who consider it an error.^[6] Its continued use in modern standard English has become more common and formally accepted with the move toward gender-neutral language.^[7][8] Some early-21st-century style guides described it as colloquial and less appropriate in formal writing.^[9][10] However, by 2020, most style guides accepted the singular they as a personal pronoun.^{[11][12][13][14]}

In the early 21st century, use of singular they with known individuals emerged for non-binary people, as in, for example, "This is my friend, Jay. I met them at work."^[15] They in this context was named Word of the Year for 2015 by the American Dialect Society,^[16] and for 2019 by Merriam-Webster.^[17][18][19] In 2020, the American Dialect Society also selected it as Word of the Decade for the 2010s.^[20]