How to use “ 难道 ” in Chinese sentences? My questions:


How to use “ 难道 ” in Chinese sentences?
What is the difference between 你不知道吗？ and 你难道不知道吗？
Grammatically, "难道" is an indication of 反问句(a rhetorical negative question). The exact correspondence in English may differ depending on the context, but I will give some examples here:


  (难道)你不知道吗？ 
  > Don't you know it? (I thought that you knew it.) 
  你(难道)不知道……吗？ 
  > Don't you know that ...... 
  (难道)你不明白吗？ 
  > Don't you understand? 
  这难道不是真理吗？ 
  > Ain't that the truth? 
  (难道)你今天不用上班吗？ 
  > Don't you have to work today? 
  你不来吗？ 
  > Aren't you coming?



Personally, I believe it's sometimes better to put 难道 in the beginning, though most of the time, the order doesn't matter in spoken language.


Questioning with a negating particle 不(not) is a negative question itself. So basically they are the same in meaning.
The possible difference is: in the second question with 难道, the speaker believes more firmly that the listener should have known (the object), to the extent that he is/would be very surprised if the listener doesn't know anything. This may also be implied in the first sentence without 难道, again, depending on the context.