GRAMMAR: who/that Use of "who" as the subject: "Who" is used to refer to persons or animate beings when they are the subject of the relative clause. Example : "The woman who is speaking is my mother. (The woman who is speaking is my mother). Use of "who" as an object: "Who" can also be used as an object in relative sentences, especially in formal English. Example: "The man who(m) I met yesterday is a doctor." (The man who(m) I met yesterday is a doctor). In formal English, "whom" can be used instead of "who" as the object. Use of "that" as the subject : "That" is used to refer to people, animals or things when they are the subject of the relative sentence. Example: "The dog that barks at night belongs to my neighbor. (The dog that barks at night belongs to my neighbor). Use of "that" as an object: "That" can also be used as an object in relativ...