Singular they

Somebody left their umbrella.

They/them/their is often used to refer to a singular indefinite person. This is common after a person, anybody/one, somebody/one, nobody/one, whoever, each, every, either, neither and no. They has a plural verb in this case.

• If a person doesn’t want to go on living, they are often very difficult to help.
• If anybody calls, take their name and ask them to call again later.
• Somebody left their umbrella in the office. Would they please collect it?
• Nobody was late, were they?
• Whoever comes, tell them I’m not in.
• Tell each person to help themselves to what they want.
• Every individual thinks they’re different from everybody else.

This singular use of they/them/their is convenient when the person referred to could be either male or female (as in the examples above). He or she, him or her and his or her are clumsy, especially when repeated, and many people dislike the traditional use of he/him/his in this situation (see here).

However, they/them/their can also be used when the person’s sex is known. Two examples from interviews:

• I swear more when I’m talking to a boy, because I’m not afraid of shocking them.
• No girl should have to wear school uniform, because it makes them look like a sack of potatoes.

They/them/their is sometimes used for a definite person who is not identified.

• I had a friend in Paris, and they disappeared for a month.

Correctness

This use of they/them/their has existed for centuries, and is perfectly correct. It is most common in an informal style, but can also be found in formal written English. Here is an example from an old British passport application form:

• Dual nationality: if the child possesses the nationality or citizenship of another country they may lose this when they get a British Passport.