I can clearly state that sentence patterns in Chinese with double negatives do not exist

Utter rubbish! Double negatives exist in spoken Chinese just as much as they do in spoken English! Try checking with a native Chinese speaker before making such rash statements!

Amused is correct, Chinese teachers tend to teach English in a pragmatic way, and as such, their grammar teaching is often better than a NES.

However, their still remains a huge issue with negatives. NES often use 'tag questions/statements' in the negative form, as in - 'We won;t go to the park this afternoon, will we?'

Chinese would essentially say - 'We won't go to the park this afternoon, yes or no?', to which the answer is a resounding 'Yes', because they are agreeing with the STATEMENT and not answering the tag question. This causes much confusion for NES because what they are essentially saying is 'Yes, we won't', and that is not what NES ears are conditioned to hear.

Take a simple statement/tag question such as, 'You failed your exam, didn't you?', and if correct, the answer is 'Yes', which is the same answer if agreeing with the statement or answering the tag question.

Turn it into negative form and say 'You didn't pass your exam, did you?', and when the answer comes back as 'Yes' (because they are agreeing with the statement and not actually answering the question), then NES become confused.

'You didn't pass your exam, did you?' = 'No' or 'No, I didn't' is what we are listening for and not 'Yes, I didn't'

Am I 'right' here, or just 'not wrong'?

Dui de? or bu cuo le?