Relative Pronouns

The relative pronouns "que" and "quien" correspond to "that," "who," and "whom." They are used to refer to a noun that has already been mentioned in the sentence. For example, in the sentence, "Hand me the book that is on the floor," the word "that" refers to the book. "Que" can be used to refer to people or things. "Quien" is used to refer only to people, but is mainly used after a preposition. It is more common to use "que" in instances where we would use "who" in English. Using "quien" in such instances is very formal. Although "que" does not change with respect to number, "quien" does. The plural form of "quien" is "quienes." Neither "que" nor "quien" change with respect to gender.

Voy a visitar a mi amiga que vive en Chile. I'm going to visit my friend who lives in Chile.
No he visto a mi tío que trabaja en Dallas. I haven't seen my uncle who works in Dallas.
Ayer vieron al muchacho a quien le dieron el libro. Yesterday they saw the boy to whom they gave the book.
Esas mujeres para quienes organizamos la fiesta nunca vinieron. Those women for whom we organized the party never came.