For instance:

> _ikenai_ → _ikenai njanai?_
>
> _tabetakunai_ → _tabetakunai njanai?_
>
> _tabetakute tamaranai_ → _tabetakute tamaranai njanai?_

Note that I'm using _**n** janai_, not just _janai_ to create a tag question.

Is this a) used? b) often? c) grammatically correct?
CC BY-SA 3.0
2018-02-10T16:16:25.263
56562
2018-03-12T19:40:15.677
2020-06-17T08:18:27.500
-1
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question
questions negation casual tag-question
Is it possible to the negative form of a verb + "n-janai" together to form a tag question?
There is no problem with using the negative form of a verb + _n janai_ to form
a tag question — in fact it is very, very common and いけないんじゃない is a good
example.

* * *

I would only say that even though 食べたくないんじゃない is perfectly grammatical, it is
not quite a real world example. A tag question is a euphemism for what you
suppose to be true.

If 食べたくない is about yourself, んじゃない suggests you are not sure about your own
state of mind. (To soften 食べたくない you can use かも(しれない), (んだ)けど, etc.)

If 食べたくない is about somebody else, you presume to have an idea about a third
person's mental state — which contradicts the "[curious unwritten rule which
states, in essence, that you cannot presume to know the intimate details of a
third person's mental state](https://japanese.stackexchange.com/a/2538/1628)".

I think this might be the reason ～たくないんじゃない has only three hits in the
[Balanced Corpus of Contemporary Written
Japanese](http://www.kotonoha.gr.jp/shonagon/) (of 1238 results for ～ないんじゃない
and 6790 results for ～たくない).
CC BY-SA 3.0
2018-02-10T19:07:51.723
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2018-02-10T19:07:51.723
1628
56562
answer