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who

pron. · n.
US //ˈhu// UK //hˈuː// who
  1. 1 asking for identity (pron.)
    A1 Beginner

    you use this to ask which person or people did something.

    an interrogative pronoun used to request the identity of a person or group of people.

    Example

    Who is that man standing by the door?

    Example

    Who was responsible for authorizing the expenditure without consulting the board of directors first?

    Usage

    Used as the subject of a sentence or question.

    Teacher's tip

    While 'whom' is technically correct for objects, 'who' is the standard choice for almost all modern spoken contexts.
    • which person
    Pitfall
    Who did you see at the party?
    Whom did you see at the party?

    In very formal English, 'who' is for the subject and 'whom' is for the object, though 'who' is now common for both in speech.

  2. 2 adding information (pron.)
    A1 Beginner

    you use this to give more details about a person you just mentioned.

    a relative pronoun used to introduce a clause that provides more information about a human antecedent.

    Example

    The woman who lives next door is a famous doctor.

    Example

    The candidates who successfully complete the first round of interviews will be invited back for a technical assessment.

    Usage

    Introduces a relative clause.

    Teacher's tip

    Remind students that 'who' is for people and 'which' is for things, though 'that' can sometimes be used for both.
    Pitfall
    The car who I bought is red.
    The car that I bought is red.

    Use 'who' only for people; use 'which' or 'that' for objects.

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  1. 3 the identity of a person (n.)
    B2 Upper Intermediate Informal

    the identity of a person, often used when the person is unknown.

    the identity or specific person involved in a situation, often used in phrases concerning mystery or investigation.

    Example

    The police are still trying to find out the who and the why of the crime.

    Example

    The mystery isn't just about the how, but the who—identifying the person behind the anonymous letters.

    Usage

    Often used in the phrase 'the who, what, where, and why'.

    Teacher's tip

    This noun use is idiomatic and usually appears alongside other question words treated as nouns.
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