* Pronoun: This is the most common use of "who." It acts as a pronoun, standing in for a noun.
* Example: "Who is coming to the party?" (Here, "who" replaces the noun "person").
* Interrogative Adjective: "Who" can also act as an interrogative adjective, modifying a noun.
* Example: "Whose book is this?" (Here, "whose" modifies the noun "book").
* Relative Pronoun: "Who" can also be a relative pronoun, connecting a dependent clause to a main clause.
* Example: "The man who lives next door is a doctor." (Here, "who" connects the dependent clause "who lives next door" to the main clause "The man is a doctor.")
So, it's important to look at the context of the sentence to determine the specific part of speech for "who."