Hi English Teacher,
This is a very interesting question.
In Chinese style, the answer is : “Yes, I haven’t.” or just “Yes” in the short form.
The first part of the sentence “Yes” directly responds to the question telling you that you are right or your question ( or guess ) is correct.
The second part “I haven’t” is the answer itself.
The first part and the second part have no relationship.
Thus we may have all four combinations in Chinese style depending on the question and situation :
“Yes, I have”
“Yes, I haven’t” ( not an English style )
“No, I have” ( not an English style )
“No, I haven’t”
However, in English, the answer of your question should be : “ No, I haven’t.”
The word “No” is independent of the question but should agree to the second part of the negative answer.
Therefore we must use “No, I haven’t” for negative answer no matter the question is a positive one or a negative one. I think this explains why you were confused in your #4 message as you expected different answers from different forms of questions. That’s true in the Chinese style but not in English.
Similarly, we use “Yes, I have” for positive answer regardless of a positive or negative question.
This is why most Chinese learners, including me, always make mistakes especially in answering negative questions in conversation without enough time for thinking.
To avoid confusion, don’t ask Chinese people with negative questions.
If their short answer is “Yes”, they probably mean “No”, and vice versa !
Good luck,
Nick