〜てはいけません must not / may not: Meaning & Examples

How 〜てはいけません works

Attach it to the て-form: ここで写真を撮ってはいけません is “You must not take photographs here.” It is the exact negative of 〜てもいいです (“you may”), and it speaks with authority. That puts it on signs, in school rules and in what parents and teachers say, rather than in a request aimed at a friend or a superior. In speech it contracts to 〜ちゃいけない (or 〜じゃいけない after a voiced て-form).

構文こうぶんConstruction

• Verb (て-form) + はいけません

  廊下を走ってはいけません。 — You must not run in the corridor.

• Plain form: Verb (て-form) + はいけない

  ここに入ってはいけない。 — You mustn’t come in here.

• Spoken contractions: 〜ては → 〜ちゃ ・ 〜では → 〜じゃ

  嘘をついちゃいけないよ。 — You mustn’t tell lies.

• The same frame asking permission: 〜てもいいですか

  写真を撮ってもいいですか。 — May I take a photo?

例文れいぶんIn a sentence

注意点ちゅういてんNuances

• Telling your manager 遅れてはいけません is not “please don’t be late” — it is an instruction. For anyone senior, use 〜ないでください.
• The は is the topic particle, so it is pronounced “wa”: 撮ってはいけません sounds like totte WA ikemasen.
• 〜てはなりません is the stiffer written twin, found on notices and in legal text. 〜てはだめ (or just だめ) is the everyday spoken end of the same scale: 走っちゃだめ.
• For a rule that applies to everyone rather than to the person in front of you, the plain 〜てはいけない reads better than the polite form. Signs use it for exactly that reason.

練習れんしゅうYour Turn

Tip

Write three library rules in Japanese with 〜てはいけません. Then rewrite one of them as something you would actually say to a friend, using 〜ちゃだめ — and notice how much the register changes.

〜てはいけません (must not / may not) in real sentences

Each one is quoted from a published Japanese text in this library and links to the story it came from. Some use older spellings, or break off where the sentence carried on. They are transcribed exactly as their authors wrote them.

Appears in 7 of 367 texts in our library.