The reality of answering いいえ to a negative question


**tl;dr** : when answering a negative question, can いいえ be used to affirm what
the question states as a whole?

I came to Japan at the age of six, and I guess I pass as a normal native
speaker of Japanese to most people (aside from some personal quirks like long
response time).

However, there's one thing, one very basic thing that I have a hard time
getting right without a conscious effort: answering negative questions.

Consider this negative question:

> 車、持ってないんですか？ You don't have a car?

The right way to answer is:

  * いいえ、持ってます / いいえ。 Yes, I have one.
  * はい、持ってません / はい。 No, I don't.

The problem is, I almost always mix up はい/いいえ and end up answering just like
in English. i.e. Describing _my_ situation rather than responding to what the
asker has in mind. With a single word answer, with no clarifying comment, it
could be a life-or-death mistake.

![Illustration](https://i.stack.imgur.com/FvD16.png)

Over the years, despite the threat of death, I've developed a self-serving
hypothesis that with most negative questions, the answer is predetermined and
anticipated by context and it doesn't matter much if I screw up. This
hypothesis seemed to work sometimes.

My question is, can I keep on believing my hypothesis? For example, if you
were asked

> もう料理はいらない？

  1. Answering はい implies what the asker has in mind "She looks full" is true; your meal is over. (the correct answer in Japanese)
  2. Answering いいえ implies you're not in the mood for another dish, just like the asker thought; your meal is over. (according to my hypothesis)

Or, is there no pathway for the kind of logic in #2 in the Japanese way of
thinking?

* * *

**Edit 1** : to clarify the scope of this question, a few bullet points if I
may...

  * Assume the question is a simple, plain negative question 
    * that is, no double negatives (...じゃないんじゃない?), confirmation in the form of a question (...じゃないですよね?), etc.
  * answered with a single word (はい/いいえ/うん/ううん)
  * taking place between true, pure-bred native Japanese speakers

**Edit 2** : thanks to the feedbacks, I've come up with a definition of the
problem in a more formal fashion. Here goes..

Conversations take place amid tensions (or harmony) between several norms:

  * Grammatical norm - the correct usage defined by grammar books
  * Social norm - accepted, default usage in practice
  * Contextual norm - accepted usage defined by context

The question is, when answering a negative question with a single word, can
contextual norm disagree with the grammatical one? i.e. can an utterance of
"いいえ" mean "はい" as defined in grammatical speak? As of this writing, one
answer says _yes_ , two others say _no_.




My understanding is that, in Japanese, you answer the question, whereas in
English, you ignore the question and just affirm or negate the predicate part.
In other words, Japanese is more logical than English, (whereas English may be
more pragmatic than Japanese).

**Japanese**

> 車を持っていますか  
> 'Is it the case that you have a car?'  
> \--はい  
>  'It is the case that I have a car.' = 'I have a car.'  
> \--いいえ  
>  'It is not the case that I have a car.' = 'I do not have a car.'
>
> 車を持っていませんか  
> 'Is it the case that you do not have a car?'  
> \--はい  
>  'It is the case that I do not have a car.' = 'I do not have a car.'  
> \--いいえ  
>  'It is not the case that I do not have a car.' = 'I have a car.'

**English**

> Do you have a car?  
> [Ignore the question. Just affirm or negate the predicate '(you) have a
> car'.]  
> \--Yes. I have a car.  
> \--No. I do not have a car.
>
> Don't you have a car?  
> [Ignore the question. Just affirm or negate the predicate '(you) have a
> car'.]  
> \--Yes. I have a car.  
> \--No. I do not have a car.

