|Look up they, them, their, theirs, or themselves in Wiktionary, the free dictionary.|
- they: the nominative (subjective) form
- them: the accusative (objective, called the 'oblique'.:146) and a non-standard determinative form.
- their: the dependent genitive (possessive) form
- theirs: independent genitive form
- themselves: the reflexive form (themself is a non-standard form that is on its way to becoming Standard English)
Old English had a single third-person pronoun hē, which had both singular and plural forms, and they wasn't among them. In or about the start of the 13th century, they was imported from a Scandinavian source (Old Norse þeir, Old Danish, Old Swedish þer, þair), where it was a masculine plural demonstrative pronoun. It comes from Proto-Germanic *thai, nominative plural pronoun, from PIE *to-, demonstrative pronoun.
By Chaucer's time the th- form has been adopted in London for the subject case only, whereas the oblique cases remain in their native form (hem, here < OE heom, heora). At the same period (and indeed before), Scots texts, such as Barbour's Bruce, have the th- form in all cases.:176
The development in Middle English is shown in the following table. At the final stage, it had reached its modern form.
|Oblique||hem||hem||hem ~ þem|
|Genitive||her(e)||her(e) ~ þeir||þeir|
Singular they is the use of they as a gender-neutral singular pronoun. In this use, they follows plural agreement rules (they are, not *they is), but the semantic reference is singular. Unlike plural they, singular they is only used for persons. For this reason, it could be considered to have personal gender. Some people refuse to use the "gender neutral" pronoun they when referring to individuals on the basis that it is primarily a plural pronoun not a singular pronoun. 
Word of the year
In December 2019, Merriam-Webster chose singular they as word of the year. The word was chosen because "English famously lacks a gender-neutral singular pronoun to correspond neatly with singular pronouns like everyone or someone, and as a consequence they has been used for this purpose for over 600 years."
- Subject: They're there; them being there; their being there; they allows for themselves to be there.
- Object: I saw them; I pointed her to them; They connect to themselves.
- Predicative complement: In our attempt to fight evil, we have become them; They eventually felt they had become themselves.
- Dependent determiner: I touched their top; them folks are helpful (non-standard)
- Independent determiner: This is theirs.
- Adjunct: They did it themselves.
- Relative clause modifier: they who arrive late
- Determiner: Sometimes, when you think, "I will show them," the them you end up showing is yourself.
- Adjective phrase modifier: the real them
- Adverb phrase external modifier: Not even them
Plural they's referents can be anything, including persons, as long as it doesn't include the speaker (which would require we) or the addressee(s) (which would require you). Singular they can only refer to individual persons. Until the end of the 20th century, this was limited to those whose gender is unknown (e.g., Someone's here. I wonder what they want; That person over there seems to be waving their hands at us.).
The pronoun they can also be used to refer to an unspecified group of people, as in In Japan they drive on the left. or They're putting in a McDonald's across the street from the Target. It often refers to the authorities, or to some perceived powerful group, sometimes sinister: They don't want the public to know the whole truth.
According to the OED, the following pronunciations are used:
In popular culture
- Them is a Northern Irish band.
- English personal pronouns
- Generic antecedents
- Object pronoun
- Possessive pronoun
- Spivak pronoun
- Subject pronoun
- Huddleston, Rodney; Pullum, Geoffrey K. (2002). The Cambridge grammar of the English language. Cambridge University Press.
- Lass, Roger, ed. (1999). The Cambridge history of the English Language: Volume III 1476–1776. Cambridge: Cambridge University Press.
- "they | Origin and meaning of they by Online Etymology Dictionary". www.etymonline.com. Retrieved 2021-03-20.
- Blake, Norman, ed. (1992). The Cambridge history of the English Language: Volume II 1066–1476. Cambridge: Cambridge University Press.
- "'He or she' versus 'they'". Oxford University Press. Retrieved 2012-07-07.
- Locker, Melissa (2019-12-10). "Merriam Webster Names 'They' As Its Word of the Year for 2019". Time. Retrieved 2019-12-10.
- Lagunoff, Rachel (1997). Singular They (Doctoral dissertation). UCLA.