这是谁的书？ zhè shì shéi de shū? - Whose book is this?
你是谁？ nǐ shì shéi? - Who are you?
谁在门外？ shéi zài mén wài? - Who is outside the door?
谁想和我一起去？ shéi xiǎng hé wǒ yīqǐ qù? - Who wants to go with me?
她是谁的朋友？ tā shì shéi de péngyǒu? - Whose friend is she?
