Someone

Someone is an indefinite pronoun in English used to refer to an unspecified person. It denotes a single, non-specific individual and is used when the speaker does not know or does not wish to identify the person. It can function as the subject of a sentence, as in "Someone rang the doorbell," or as the object, as in "I spoke with someone in the hall." Its possessive form "someone's" indicates ownership, as in "someone's bag."

Etymology and form: The word combines some and one. The compound appeared in Middle English and gradually took a single-word form. Today "someone" is the standard written and spoken form in most varieties of English; historically, "some one" appeared in earlier texts, but the two-word form is now rare.

Usage notes: In modern English, someone is generally interchangeable with "somebody," though some registers may prefer one over the other. "Someone" is often viewed as slightly more formal or literary in some contexts. It contrasts with "no one" or "nobody," which negate the existence of a person.

See also: Indefinite pronoun; no one; somebody; anybody.