〜てはいけない

must not; prohibited from...

1. Overview

「〜てはいけない」 is a Japanese expression used to indicate that doing something is prohibited or not allowed. It emphasizes that a certain action is considered inappropriate and therefore should not be performed.

2. Structure

• Grammar Structure:

  • Verb (て-form) + はいけない

• Explanation: This structure is used to clearly express that a particular action is forbidden, often used for warnings, admonitions, or regulations.

3. Usage Explanation

• Connection: Commonly used in both spoken and written language to indicate that a certain activity is not allowed.

• Translation: It is generally translated as "must not...", "cannot...", or "forbidden...".

4. Example Sentences

1. ここでタバコを吸ってはいけない。
   You must not smoke here.

2. 遅刻してはいけません。
   You must not be late.

3. 人の話を聞かずに自分の意見を言ってはいけない。
   You must not speak your opinion without listening to others.

4. 運転中に携帯電話を使ってはいけない。
   You must not use your mobile phone while driving.

5. 宿題を忘れてはいけません。
   You must not forget to do your homework.

5. Alternative Grammar

• Another way to express 〜てはいけない is 〜てはいけません, which is more formal.
  • Example: ここでは飲食をしてはいけません。
    You must not eat or drink here.

6. Related Grammar

• 〜てはならない: A more formal and severe form of prohibition.
  • Example: 危険なことをしてはならない。
    You must not do dangerous things.

7. Notes

• Context: 「〜てはいけない」 is used to indicate clear prohibitions and is applicable in various situations.

• Tone: This expression typically carries a warning or directive tone, emphasizing that a certain action is not allowed.

8. Summary

「〜てはいけない」 is a structure used in Japanese to express prohibition or the unacceptability of certain actions. It can be used in everyday communication and formal contexts to clearly convey what is forbidden.