someone
n.n. an unknown or unnamed person. You use this when you are talking about a person but you do not know exactly who they are.
n. an unspecified or unknown person. Functions as an indefinite pronoun; used primarily in affirmative clauses or in questions where a positive response is anticipated.
Someone is knocking at the door.
I need someone to help me carry these heavy boxes to the car.
The witness reported seeing someone lurking near the entrance shortly before the alarm sounded, though they could not provide a detailed description.
From Middle English sum on, sum one, sum oon, equivalent to some + one.
Indefinite pronoun. Typically takes a singular verb, even when referring to multiple people or when using 'they' as a gender-neutral singular pronoun.
Is someone there? No, someone isn't here.Is someone there? No, no one is here.In negative statements, 'no one' or 'anybody' is used instead of 'someone'.