一般涉及到提问的目的,如语言方面的:What's the past tense of 'to sing'? Is this right? What's the answer to number 6? 理解方面的: What is Mrs Lane doing in the picture? When does Mr Mason go to work? 提问意见与爱好:What did you think of the song? Do you agree with Tim? Who is your favourite singer?