いけない · i-adjective
| Form | Positive | Negative |
|---|---|---|
| Dictionary | いけない | いけなくない |
| Polite | いけないです | いけなくないですalso いけなくありません |
| Past polite | いけなかったです | いけなくなかったですalso いけなくありませんでした |
| Past | いけなかった | いけなくなかった |
| Te-form | いけなくて | いけなくなくて |
| Adverbial | いけなく | |
| Conditional | いけなければ | いけなくなければ |
| Tara conditional | いけなかったら | いけなくなかったら |
Used to describe behavior or situations that are morally or socially unacceptable. Often used when scolding children or expressing disapproval.
そんなことをしてはいけません。
You mustn't do such a thing.
Telling lies is wrong.
must not; should not; ought not to
Attaches to the -te form of a verb or adjective to express prohibition or strong advice against doing something.
You must not take photos here.
We shouldn't be late, so let's leave early.
Expresses that something is not working, not acceptable, or beyond repair. Sense 4 (hopeless) is a stronger extension of this meaning.
This computer seems to be no good anymore.
It's no use asking him.
unfortunate; a shame; a pity
Used to express sympathy or regret about a situation. Often appears as いけないね or いけないことになった.
The sports day was canceled because of rain. That's a shame.
unable to drink (alcohol)
Specifically refers to being unable to handle alcohol; a set expression often used as お酒がいけない.
I can't drink alcohol.
so as not to ...; lest ...; in case ...
Used in the pattern ...すると/してはいけないから/ので to express doing something to prevent an undesirable outcome.
Let's write it down so we don't forget. Just in case.
いけない is the standard Japanese expression for prohibition, while あかん is the Kansai dialect version used in casual speech.