〜てはいけない
JLPT N5:must not
Says something is not allowed: "you must not…". It sounds like a rule.
How to form it
- Put the verb in the て-form and add はいけない, or はいけません to be polite: 吸う becomes 吸ってはいけません.
- In casual speech ては becomes ちゃ and では becomes じゃ: 吸っちゃいけない, 飲んじゃいけない.
- だめ can replace いけない: 触ってはだめ.
Examples
ここでタバコを吸ってはいけません。
You must not smoke here.
授業中に話してはいけません。
You must not talk during class.
Notes
- Because it states a rule, it can sound strict when said to one person. For a personal request, 〜ないでください is softer.
Similar meaning
- 〜てもいいmay / it's OK to
The opposite: permission.
- 〜ないでくださいplease don't
A polite personal request not to do something.