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

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

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

1. Introduction

The grammar structure ～てはいけない (〜te wa ikenai) is used in Japanese to express prohibition or to indicate that something is not allowed. It is commonly used in both spoken and written Japanese.

2. Core Grammar Explanation

Detailed Explanation

• Meaning: "must not," "should not," or "is not allowed to"
• Structure:
  • Take the verb, change it to the て-form (te-form), and add はいけない (wa ikenai).
  • The structure can be broken down as follows:
    • Verb (て-form) + はいけない (wa ikenai)

Formation Diagram

Visual Aids

• Prohibition can be succinctly understood as:

  Verb (て-form) + はいけない
  

  • Example: 食べて + はいけない → 食べてはいけない

3. Comparative Analysis

Differences with Similar Grammar Points

• ～ないでください (〜naide kudasai): This also indicates prohibition but is more polite. It can be translated as "please do not..."
  • Example: 食べないでください (tabenaide kudasai) - "Please do not eat."
• ～てはならない (〜te wa naranai): This expression carries a similar meaning but is stronger in conviction, often used in legal or formal contexts where strict rules are applied.
  • Example: 構造を変更してはならない (kouzou o henko shite wa naranai) - "You must not change the structure."

4. Examples in Context

Sentence Examples

• Formal:

  1. ここでタバコを吸ってはいけない。
     (Koko de tabako o sutte wa ikenai.)
     "You must not smoke here."

• Informal:

  2. 今、遊んではいけないよ。
     (Ima, asonde wa ikenai yo.)
     "You shouldn’t play right now."

• Written:

  3. この文書をコピーしてはいけない。
     (Kono bunsho o kopii shite wa ikenai.)
     "You must not copy this document."

• Spoken:

  4. 宿題を忘れてはいけないよ。
     (Shukudai o wasurete wa ikenai yo.)
     "You must not forget your homework."

5. Cultural Notes

Cultural Relevance

In Japanese culture, following rules and regulations is highly valued, and using ～てはいけない emphasizes respect for these societal norms. This structure is often used by teachers or parents to teach children what behaviors are unacceptable.

Levels of Politeness and Formality

• Casual: Just using the te-form + いけない (ikenai) is suitable for conversations among friends or close acquaintances.
• Polite/Formal: In formal requests or rules, it is advised to use appropriate honorifics or structures, depending on the audience.

Idiomatic Expressions

• "してはいけない" (shite wa ikenai) can appear in various contexts, highlighting what actions are unacceptable.

6. Common Mistakes and Tips

Error Analysis

• Using dictionary form: Many learners mistakenly use the dictionary form of the verb instead of the te-form.
  • Wrong: 食べてはいけない (✓) vs 食べるはいけない (✗)

Learning Strategies

• Mnemonic Device: Remember that "いけない" sounds like "I cannot," which helps in reminding that it's about prohibition.
• Practice converting verbs to the te-form regularly to gain familiarity.

7. Summary and Review

Key Takeaways

• Meaning: Prohibition (must not, should not)
• Structure: Verb (te-form) + はいけない
• Use in both formal and informal contexts based on audience.

Quick Recap Quiz

1. What is the te-form of "飲む" (nomu)?
   • a) 飲んで (onde)
   • b) 飲み (nomi)
   • c) 飲んでは (nonda)
2. Translate: "You must not smoke here."
   • a) ここでタバコを吸ってはいます。
   • b) ここでタバコを吸わない。
   • c) ここでタバコを吸ってはいけない。 Answers:
3. a) 飲んで (onde)
4. c) ここでタバコを吸ってはいけない。