Processing keyword: ～てはいけない (〜te wa ikenai)

Japanese Grammar Point: ～てはいけない (〜te wa ikenai)

1. Introduction

The grammar point ～てはいけない (〜te wa ikenai) is an essential construct in Japanese that expresses prohibition. It is used to tell someone that they must not do something or that something is not allowed.

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2. Core Grammar Explanation

Detailed Explanation

• Meaning: "You must not do..." or "It is not allowed to..."
• Used to express strong prohibition or to forbid an action.
• Commonly found in rules, regulations, and when giving strict instructions.

Formation

To form this structure, attach 〜てはいけない to the て-form of a verb.

Structure:

[Verb in て-form] + はいけない

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Visual Aid

Formation Table

Verb (Dictionary Form)	て-form	+ はいけない	Meaning
食べる (taberu)	食べて (tabete)	食べてはいけない	You must not eat
行く (iku)	行って (itte)	行ってはいけない	You must not go
入る (hairu)	入って (haitte)	入ってはいけない	You must not enter
話す (hanasu)	話して (hanashite)	話してはいけない	You must not speak/talk

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3. Comparative Analysis

• ～てはいけない vs. ～てはならない

  • Both express prohibition.
  • ～てはならない is more formal and strict, often used in written rules or laws.

• ～てはだめだ

  • Less formal than ～てはいけない.
  • Common in casual speech to friends or family.

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4. Examples in Context

Sentence Examples

1. Classroom Setting (Formal)
   • Japanese: 授業中に携帯電話を使ってはいけません。
   • Romaji: Jugyō-chū ni keitai denwa o tsukatte wa ikemasen.
   • English: You must not use your mobile phone during class.
2. Library Notice
   • Japanese: ここで飲食をしてはいけない。
   • Romaji: Koko de inshoku o shite wa ikenai.
   • English: You must not eat or drink here.
3. Parental Advice (Informal)
   • Japanese: 夜遅くまで起きてはいけないよ。
   • Romaji: Yoru osoku made okite wa ikenai yo.
   • English: You shouldn't stay up late at night.
4. Workplace Rule
   • Japanese: 社内の情報を外部に漏らしてはいけない。
   • Romaji: Shanai no jōhō o gaibu ni morashite wa ikenai.
   • English: You must not leak company information to outsiders.
5. Traffic Sign
   • Japanese: ここに駐車してはいけません。
   • Romaji: Koko ni chūsha shite wa ikemasen.
   • English: Parking here is not allowed.

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5. Cultural Notes

Cultural Relevance

• Politeness Levels: Using ～てはいけません is the polite form suitable for formal situations and written instructions.
• Social Norms: In Japanese culture, indirectness is common, but prohibitions using this grammar point are direct and leave no room for ambiguity.

Idiomatic Expressions

• 毒を食らわば皿まで (Doku o kurawaba sara made)
  • Literally: "If you eat poison, eat the plate too."
  • Implies: If you're going to do something bad (which you shouldn't), you might as well go all the way.
  • Though not using ～てはいけない, it touches on the idea of forbidden actions.

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6. Common Mistakes and Tips

Error Analysis

1. Using the wrong verb form
   • Incorrect: 食べるはいけない。
   • Correct: 食べてはいけない。
   • Always use the て-form of the verb before attaching はいけない.
2. Misplacing particles
   • Incorrect: 食べていけない。
   • Correct: 食べてはいけない。
   • Don't omit the particle は.

Learning Strategies

• Mnemonic Device: Think of "Te-form + wa ikenai" as "Te-way to Ike (no go)nai (no way)**" – a way to remember that it's about not going/doing.
• Practice: Create sentences about school or workplace rules to become familiar with the structure.

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7. Summary and Review

Key Takeaways

• ～てはいけない is used to express strong prohibition.
• Formed by adding はいけない to the て-form of a verb.
• More formal than ～てはだめだ, less formal than ～てはならない.

Quick Recap Quiz

1. How do you say "You must not run in the hallway" in Japanese?
2. Which form of the verb is used with ～てはいけない?
3. Is ～てはいけない more formal or less formal than ～てはならない?

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Answers:

1. 廊下を走ってはいけない。 (Rōka o hashitte wa ikenai.)
2. The て-form of the verb.
3. Less formal.

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