N3 · Structured courses

～Beki Dewa Nai: Should Not

Learn the negative of beki — "should not" based on morals or common sense. 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 the negative of beki — "should not" based on morals or common sense.
  • Form and connection: [Verb辞书形] べきではない
  • Nuance in real use: べき and べきではない are rare moral judgment grammar in Japanese — not "would you" but "should you." In Japan, using べき to advise someone requires care because it carries a sense of moral authority.

Form and connection

[Verb辞书形] べきではない

Core Explanation

Learn the negative of beki — "should not" based on morals or common sense.

Cultural Note

べき and べきではない are rare moral judgment grammar in Japanese — not "would you" but "should you." In Japan, using べき to advise someone requires care because it carries a sense of moral authority.

Practical examples

One should not tell lies.
You shouldn't say things that hurt people.
I should have come earlier.

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辞书形] べきではない
2. Explain the meaning of the first example.
Show answerOne should not tell lies.
3. Rewrite the final example using this lesson pattern.
Show answerもっと早はやく来くるべきだった。 ([Verb辞书形] べきではない)

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