1. A method, implemented on at least one computing device, each of which has at least one processor, storage, and a communication platform connected to a network for classifying a question, the method comprising: receiving a question from a person; extracting at least one feature from the received question; determining a question pattern based on the at least one feature extracted from the question; retrieving a model selected based on the question; checking for a match between the at least one feature and information related to the person; and determining that the question is a personal question based on the match, the question pattern, and the selected model.