A few uses of 〜じゃない

As most people who have studied a little Japanese know, じゃない is an expression in Japanese that means “is/are not” and is be the opposite of だ (the copula, or “is”). In this post I’ll go over a few different ways to use じゃない. (じゃない happens to be an abbreviation of “ではない”, though that isn’t related to the material in this post)

First, an example sentence for the basic meaning of “is/are not”.

• 僕はアメリカ人じゃない。
• I’m not an American.

You can also use じゃない after の (or ん）to negate a statement.

• そういう事を言ってるんじゃない。
• I’m not saying that.

Here the ん is an abbreviation of の, which is being used in a similar way to わけ. In fact, you could replace ん with わけ, and have pretty much the same meaning.

If you change the じゃない after の (or ん） to “じゃなかった?”, you can express that you thought someone would do something (but didn’t).

• 君、日本に行くんじゃなかった？
• I thought you were going to go to Japan?

You can use a similar pattern to express that you wish you hadn’t done something. All you need to do is change the verb before the ん to past tense, and change the intonation at the end of the sentence from a question to something more firm.

• 君に教えたんじゃなかった！！
• I shouldn’t have told you!!

Another way to use じゃない is when you suspect something or have a hunch.

• 実は、この授業が難しいんじゃないかなと思ってたよ
• Actually, I was thinking that this class might be difficult.

A more literal (and less natural) translation would look like this:

• Actually, I was wondering if it wasn’t the case that this class is difficult.

Another common usage of じゃない is to try to convince someone of your feelings about something by asking a rhetorical question.

• すごい (ん)じゃない(か)?
• Isn’t that awesome?

The polite form of this would be “~じゃないですか？”. Conversely, you could shorten it to simply じゃん as is done by younger people.

• すごいじゃん！
• Isn’t that awesome!

You can use this in a similar way when answering a question in a noncommittal way.

• ね、パーティーにこのドレスを着て行っていいと思う？
• Hey, do you think it’s OK for me to wear this dress to the party?
• いいんじゃない？
• Sure, why not.

Based on this type of response, the person answering doesn’t have a particularly strong feeling about the dress.

In written Japanese, or polite/formal spoken Japanese, the full のでない is sometimes used, and the ん before it can be written out fully as の. In cases like this there is an interesting abbreviation that occurs when someone is trying to suggest something politely.

• 友達と日本語の勉強をするといいのでは？
• Maybe it would be good to study Japanese with your friend?

The here のでは would be short for 〜のではないですか？ or ~のではないでしょうか？