いけない

Japanese

Etymology

From 行ける.

Adjective

いけない (い-i inflection, romaji ikenai)

1. bad, naughty
   • いけない子だね。
     You're a naughty child.
2. it's bad if...
   • 宿題をしなくてはいけない。
     I have to do my homework. (it's bad if I don't do my homework)
   • ポイ捨てしてはいけない。
     Please don't litter. (it's bad if you litter)
   • Note: This sense is similar to ならない, but appeals to morals instead of rules. してはならないこと is something you're not allowed to do, and してはいけないこと is something that you shouldn't do because it brings about an unwanted result. However, this doesn't mean that いけない in e.g. ポイ捨てしてはいけない makes it just a request instead of a demand, any more than please in "please don't litter" makes that so.
3. Oh no!
   • いけない、遅刻する！
     Oh no! I'm gonna be late!

Synonyms

• 悪い
• ならない
• 駄目
• 明かん