N4 · Structured courses

Te Wa Ikenai: Must Not

Learn てはいけない/ならない/だめ for prohibition (rules-based). This lesson combines form, context, examples, common mistakes, and practice so you can use the pattern in real communication.

12 minNihongo Hub Editorial TeamPublished 2026-06-06Updated 2026-06-06

Learning objectives

  • Lesson goals: Learn てはいけない/ならない/だめ for prohibition (rules-based).
  • Form and connection: [Verb te-form] は + だめ/いけない/ならない
  • Nuance in real use: These three prohibition forms create a gradient of "can't" — from gentle reminder (だめ) to serious rule (ならない) — drawing society's boundary lines.

Form and connection

[Verb te-form] は + だめ/いけない/ならない

Core Explanation

Learn てはいけない/ならない/だめ for prohibition (rules-based).

Cultural Note

These three prohibition forms create a gradient of "can't" — from gentle reminder (だめ) to serious rule (ならない) — drawing society's boundary lines.

Practical examples

You must not run in the classroom.
You can't take photos here.
You must not forget your promises.

Common pitfalls

Build the base form before adding the pattern

Complete the required conjugation first. Do not keep polite and plain endings at the same time.

Match politeness to the situation

The examples are reliable starting points; relationships and context can still change the most natural wording.

Practice and answers

1. Write the connection formula for this lesson.
Show answer[Verb te-form] は + だめ/いけない/ならない
2. Explain the meaning of the first example.
Show answerYou must not run in the classroom.
3. Rewrite the final example using this lesson pattern.
Show answer約束やくそくを忘わすれてはなりません。 ([Verb te-form] は + だめ/いけない/ならない)

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