who vs. that for people

For a person, the standard relative pronoun is who: the electrician who wired the new garage. Using that for a person is widespread in conversation, but many people regard it as careless and judge anyone who uses it. The same ruling applies after anyone, someone, and those: anyone who registers late.

Three kinds of antecedent fall outside the ruling.

An organization or group treated as a unit takes that in a restrictive clause and which in a nonrestrictive one: the firm that audited the charity.

When one clause describes both people and things, use that in either order: the musicians and instruments that crowded the stage.

A pet, or any animal with a name, takes who, and any other animal takes that or which: our parrot, Kiwi, who whistles at the mail carrier, but the hawk that nests under the bridge.

In a cleft sentence, it is or it was puts one element of the sentence in focus, and a clause follows it. When the focused element is a person, the preference for who holds: It was the night nurse who noticed the rash.

See also who / whom; that / which; restrictive / nonrestrictive clauses; comma with nonrestrictive clauses; cleft sentences; whose for things; one of those who.