AI Glossary / Natural language and speech / Intermediate
Singular they
Definition
Singular they is the use of “they,” “them,” “their,” or related forms to refer to one person. It can refer to an unspecified person whose gender is unknown or irrelevant, or to a particular person who uses they/them pronouns. Language systems must distinguish this use from plural reference through context.
What it means
English pronoun form does not always map directly onto the number of people being discussed. In “A visitor left their umbrella,” “their” can refer to one visitor even though the same form also occurs with plural referents.
Singular they also applies to known individuals who use these pronouns. The meaning should not be treated as an incomplete plural reference merely because the form is familiar from sentences about groups.
For AI, this is a practical language-understanding issue. A rigid rule that “they” must refer to several people can break coreference resolution, distort summaries, or make a writing assistant suggest inappropriate changes to otherwise suitable sentences.
How it works
Determine the referent from the sentence and surrounding discourse rather than relying on the pronoun alone. An indefinite expression such as “a participant” may license singular they, while a stated individual reference or known pronoun information can guide interpretation in other cases.
Verb agreement follows the normal form used with “they”: “they are” and “they have,” even when one person is intended. A singular noun or name still takes its appropriate singular agreement, as in “the participant is.”
Coreference systems need to represent the difference between grammatical form and referent number. Generation systems should preserve the intended person and pronouns rather than changing them to satisfy an oversimplified agreement rule.
If the reference is ambiguous, clarify it from context or use an appropriate explicit name; do not invent identity information.
Three practical examples
- A form instruction says, “Each applicant should keep their confirmation email,” without assuming an applicant’s gender.
- A summarizer preserves they/them pronouns used for a named person in the source document.
- A coreference evaluation includes singular and plural uses of “they” to check whether the model follows the intended referents.
Think of it this way
Think of a label whose interpretation depends on the item it is attached to, rather than on its shape alone. The same visible form can point to one person or several. The analogy is limited because pronoun interpretation involves grammar, discourse, and personal usage, not a mechanical lookup from one word to one fixed number.
Worked example
Consider an invented passage: “Morgan uses they/them pronouns. Morgan submitted the draft. They are waiting for feedback.” The final “They” refers to Morgan, one person.
A correct entity cluster can group the relevant occurrences of “Morgan” and “They.” The plural-form verb “are” does not require the system to create an additional person or reinterpret Morgan as a team.
Now compare “Morgan and Jules submitted the draft. They are waiting for feedback.” Here “They” naturally refers to the two-person group introduced in the first sentence.
The pronoun and verb forms are the same in the two endings, but their intended reference differs. A rule based only on “they are” cannot distinguish the examples.
Finally, “A reviewer may request a revision if they find an error” uses singular they with an unspecified reviewer. It does not identify a particular reviewer or justify inferring that person’s gender identity. The examples demonstrate reference interpretation rather than a demographic classification task.
Illustrative case study
In a fictional project, Fern Editorial tests an AI assistant that shortens staff biographies. A source biography consistently uses they/them pronouns for a named person, but one generated summary changes the pronoun to “he.”
Reviewers identify the change as a failure to preserve the source’s reference information. They add examples that separately test singular they, plural they, and ambiguous references requiring careful wording.
The imagined project illustrates an editing and coreference requirement. It does not assume that every occurrence of “they” signals a particular identity, nor that pronouns should be inferred from names, photographs, or job titles.
Common misconceptions and mistakes
Singular they does not mean that one person is being described as multiple people. The referent is singular even though some grammatical forms resemble plural usage.
It is not limited to unknown people: it can be used for a specific person who uses those pronouns.
It also does not require the verb phrase “they is.” Standard usage retains “they are.”
Finally, pronoun usage alone is not a reliable basis for inferring every aspect of someone’s gender. The language-processing task is to understand and preserve the supplied reference, not to invent personal attributes.
Business use
Handling singular they correctly matters for writing assistants, translation workflows, search, summarization, and customer communication. Failures can make text inaccurate or cause a system to split one person into several entities.
Evaluation should include clear singular and plural examples, generic references, and passages where the correct link depends on context. Review both reference accuracy and whether generated text preserves the source’s stated pronouns.
Product teams can also check whether grammar suggestions incorrectly flag accepted singular-they constructions. Explanations should help users understand the sentence rather than imposing a simplistic rule that all “they” references must be plural.
People also ask
Should I write “they is” when referring to one person?
No. Use forms such as “they are” and “they have,” while a singular name still takes forms such as “Morgan is.”
Can “their” refer to one person?
Yes, as in “A guest should collect their badge.”
Does singular they always refer to a nonbinary person?
No. It can also refer generically to someone whose gender is unknown or irrelevant to the statement.
Check your understanding
“A customer called. They asked for a replacement.” Does the second sentence necessarily describe several customers?
Answer: No. “They” can refer to the single customer introduced in the first sentence. The context supports a singular interpretation.
Related terms
- Pronoun
- Coreference resolution
- Anaphora
- Referent
- Natural language generation
- grammatical agreement
- semantic number
- inclusive language
- reference preservation
Learn next
Learn how pronouns connect to their referents, then compare singular and plural uses in short passages. Study the distinction between agreement form and semantic number. When evaluating generated text, check whether the system preserves explicit reference information rather than replacing it with assumptions.
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Sources
APA Style, official guidance on singular “they,” forms, and agreement: https://apastyle.apa.org/style-grammar-guidelines/grammar/singular-they. Jurafsky and Martin, Speech and Language Processing, coreference and number-agreement discussion: https://web.stanford.edu/~jurafsky/slp3/24.pdf. Independent review checked APA’s singular-they forms and verb-agreement guidance.
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