They / them
A singular pronoun for a person, in English since the 1300s.
They and them are used as singular pronouns for a specific person. Someone whose pronouns are they/them is referred to as they, not he or she: they are running late, I asked them, that coat is theirs.
The grammatical objection has an awkward history. Singular they appears in English from the fourteenth century, in Chaucer, in Shakespeare, in Austen and in the King James Bible. Everyone already uses it without noticing, in sentences like somebody left their umbrella. The objection tends to arrive only when the person referred to is known.
It covers two different uses. The generic one, for a person whose gender is unknown, has never been contested in practice. The specific one, for a known person who uses they, is the newer application and the one people trip over.
Tripping over it is normal for a while and is not the problem. The correction is the whole of the etiquette: say the right pronoun, carry on with the sentence, and do not make the other person manage your embarrassment.
Not every nonbinary person uses they, and not everyone who uses they is nonbinary. Some use he or she, some use both, some use neopronouns, some use their name in place of a pronoun.
Singular they is not new
The grammatical argument assumes the singular use arrived recently along with the politics. It is in English from the 1300s and has been in continuous use since, including by every writer usually cited in defence of proper grammar.
What is new is using it for a specific, known person rather than a hypothetical one. That is a real change in usage, and it is a much smaller one than the grammar argument suggests.
Saying it well
Say this
- They are running late.
- I asked them and they said yes.
- My pronouns are they/them.
- Sorry — they. Anyway, as I was saying.
Not this
- They is plural, it is not grammatical
- It
- He/she
- So what are you really?
Questions people actually ask
How do you use they/them for one person?
Exactly as you would for a group, with plural verb forms: they are, they were, I asked them.
Is singular they grammatically correct?
Yes, and it has been in English since the 1300s, including in Chaucer, Shakespeare and the King James Bible.
What do I do if I get it wrong?
Correct yourself, continue the sentence, and do not turn it into an apology the other person has to manage.
Does everyone nonbinary use they/them?
No. Some use he or she, some use several sets, some use neopronouns, some use their name.
Can someone use more than one set of pronouns?
Yes. She/they and he/they are common, and usually mean either is fine unless the person says otherwise.