Negative questions and tag questions

Customer Service: Don’t you receive the material ?
Silly Me: Yes, I don’t !!!
You may be surprised with an answer like mine. In my native language (Vietnamese), it is totally correct but not in English. Instinctively, I think my response is to agree or disagree with the question (Yes, I agree with you I don’t receive the material yet). In English, my answer should reflect the truth, however.
In other words, I should say in English:
I don’t receive the material -> NO
I do receive the material -> YES.
Funny me
It is also awkward for me to answer tag questions:
Snow is white, isn’t it?
Snow isn’t white, is it?
Both answers are: YES, IT IS
According to EnglishClub.com:
Answer a tag question according to the truth of the situation. Your answer reflects the real facts, not (necessarily) the question.
Also there is a joke told by Professor Mayfair in mayfairschool.co.uk:
Only the other day, as a joke, I asked a class ‘Wouldn’t you like me to give you extra homework tonight?’ I was very surprised when the whole class answered in one voice ‘Yes!’. I knew that they did not want more homework so why did they give this answer? My students were confused because the question was not the usual one that they were used to i.e. ‘Would you like me to give you extra homework tonight?’ As a result of this confusion, they said ‘Yes’, when really they meant ‘No!’
Fortunately the way to avoid this confusion is very simple…The trick is to remember that although the question may be positive or negative,
Your answer does not change, the answer depends on you not the question
. Thinking about the auxiliary that follows the word ‘Yes’ or ‘No’ helps too, please note that, as in both conversations above, the auxiliary must always be positive if your answer is ‘Yes’ and negative if your answer is ‘No.’
In other words ‘Yes’ always means yes and ‘No’ always means no!