Definition

1. Pronoun (Interrogative):

   • Used to ask about the identity of a person or people.
   • Used to inquire which person or people are involved in an action or situation.

2. Pronoun (Relative):

   • Used to introduce a clause giving further information about a person or people previously mentioned.

Usage

• As an Interrogative Pronoun: "Who" is used to form direct or indirect questions about people.
  • Who is at the door?
  • I wonder who will be there.
• As a Relative Pronoun: "Who" is used to connect a relative clause to a noun or pronoun referring to a person. It can function as the subject or object of the relative clause.
  • The woman who called you is my boss. ("who" is the subject of "called")
  • The person who you met is my neighbor. ("who" is the object of "met"; in formal English, "whom" is preferred here).

Examples

• Interrogative:
  • Who told you that secret?
  • Can you tell me who is responsible for this project?
• Relative:
  • She is the scientist who discovered the new element.
  • The students who passed the exam were very happy.

Advanced Usage

• "Who" vs. "Whom": In modern English, especially in informal contexts, "who" is often used for both the subject and object positions. However, in formal writing, "whom" is traditionally used when the pronoun is the object of a verb or preposition.
  • Informal/Common: Who did you invite?
  • Formal: Whom did you invite? or To whom did you speak?
• "Who" in defining vs. non-defining clauses: "Who" is used in both types of relative clauses.
  • Defining (essential information): The man who lives next door is a doctor.
  • Non-defining (extra information, set off by commas): My sister, who lives in Paris, is visiting us.

Variants and Related Words

• Whom (pronoun): The objective case of "who," used formally when referring to the object of a verb or preposition.
• Whoever (pronoun): Used to mean "any person who" or "no matter who."
  • Whoever arrives first can choose a seat.
• Whose (pronoun): The possessive form of "who" and "which," used to indicate belonging.
  • That's the artist whose work I admire.

Synonyms

• Interrogative: Which person? What person?
• Relative: That (when referring to people, though "who" is more specific and common).

Related Phrases

• "Who's who": A phrase referring to a list or description of notable people and their identities.
  • The event was a gathering of the city's who's who.
• "Who knows?": A rhetorical question expressing uncertainty.
  • Who knows what the future will bring?

Notes

• The reference definition provided ("a United Nations agency...") is for the acronym WHO (World Health Organization), which is a proper noun and a different lexical item from the pronoun who. This explanation covers only the pronoun "who."

Noun

1. a United Nations agency to coordinate international health activities and to help governments improve health services