はいけない

Phrase (Basic ㊦ 528)

A phrase which indicates prohibition.

Equivalent: Cannot do something; must not do something; don’t do something; should not do something

この部屋に入ってはいけない・いけません。
You must not enter this room.
教室でものを食べてはいけません。
You must not eat (food) in the classroom.
花子はまだ酒を飲んではいけない。
Hanako must/can not drink alcohol yet.

Formation

Vて はいけない  
  話してはいけない Must not talk
  食べてはいけない Must not eat

Notes

1. In Verbてはいけない, the second person subject is usually omitted, as in Key Sentence and Example (a).

2. Verbてはいけない is often used as a negative answer to "Verbてもいいです (May I ~?)."

(⇨ てもいい)

【Related Expression】

Verbてはならない also expresses prohibition. Verbてはならない, however, sounds a little stronger than Verbてはいけない.