어디서 중요한 전화 올 데가 있어? = Do you have somewhere to call from? = Is there any phone call that you are waiting? 데 means "place,point,thing,matter,part,aim" ㄹ 데 means "somewhere to do something" e.g. 갈 데가 있어? = Do you have somewhere to go? = Is there any place that you are supposed to go?