じゃないか (ja nai ka) Meaning Japanese Grammar - Isn't It?

Author Anna Baffa Volpe for article 'じゃないか (ja nai ka) Meaning Japanese Grammar - Isn't It?'

Anna Baffa Volpe

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じゃないか (ja nai ka) Meaning Japanese Grammar - Isn't It?

The structure じゃないか (janaika) is a negative interrogative form and means isn't it?, right?.

It is preceded by nouns, adjectives and verbs.

In this post we learn more about the meaning of じゃないか, how it is formed and when じゃないか is used through real example sentences.

How and when to use じゃないか

This structure is used to express emotions such as surprise at something unexpected, but also blame and anger depending on the situation.

With this form you also ask your interlocutor for confirmation of what you are saying.

It is true, isn't it? Right?

Expression: いいじゃないか: Why not? It's fine, isn't it?, Never mind.

いいじゃないか? It's good, isn't it?


It doesn't matter if you're wrong.

How じゃないか is formed

じゃないか is formed:

  • by じゃない or ではない, negative forms of the copula だ
  • and by the interrogative particle

ではないか is more formal than じゃないか.


()(けい)() refers to recession, crisis and (えい)(きょう) means influence, effect, impact


This is the recession’s effect, isn't it?

Adjective in い+じゃないか

(たか)Adjective in い, means high, expensive, expensive


This restaurant is expensive, isn't it?

Adjective in な without な+じゃないか

()(てき)Adjective in な means beautiful, magnificent, splendid

Title of a CD by The Beach Boys: 『Wouldn't It Be Nice』

Isn't that lovely?
()(てき)な: beautiful, nice


Wouldn't it be nice?

(じゅう)(ぶん)な means enough, sufficient


Isn't that enough?



You did all the cooking by yourself, didn't you?

With adjectives ending in い and verbs we often find the form んじゃないか.


It's a nasty wind, isn't there a typhoon coming?


The way he spoke made me think he was a doctor.

Volitive / exhortative form and じゃないか

Another common structure is formed by じゃないか or ではないか combined with the volitive / exhortative form of the verb. We translate this form as: come on let's do!, why don't we do?

Volitive form in よう - おう+じゃないか

Ichidan verbs: the volitive form is obtained by removing the syllable and adding よう.

  • Why don't we eat?
  • Come on, let's eat! Godan Verbs: the Volitive form uses the Base in お or B5 + the vowel う.
  • Let's drink come on!
  • Why don't we drink?


Let's listen to him until the end, shall we?


I'm a bit tired, so why don't we have a little rest around here?

  • Since I'm a bit tired, let's rest here for a moment!


Why don't we eat, drink and have fun today?

In this last sentence we find a form commonly used in Japanese: たり~する to list a sequence of actions.


If no one else will do it, I will do it.

  • If no one does it, it means that I will.

Examples of じゃないか


I can't get through on the phone at all. Perhaps the number is wrong.


Isn't it the opposite?


You broke your computer.