Qu est-ce que tu Fais le soir?

"Qu'est-ce que tu fais le soir?" "What are you doing tonight?"

Actually this would mean "What do you do at night," in the sense of what you generally do most evenings. If you want to ask what somebody is doing tonight, it's Qu-est-ce que tu fais ce soir or Que fais-tu ce soir.