べきだbeki da“should do; must do”

べきだ means should do; must do; have a duty to ~. It is a JLPT N3 grammar pattern used to state an obligation, strong recommendation, or moral duty.

This grammar point often appears in neutral to formal Japanese. If you want to state a strong moral or logical obligation, べきだ is a useful pattern to learn.

What does べきだ mean?

Use べきだ when you want to state an obligation, strong recommendation, or moral duty.

Natural translations include:

• should do; must do ~
• should do; must do; have a duty to ~
• should do; must do

How to form べきだ

Verb dictionary form + べきだ (する → すべき / するべき)

Examples of the pattern:

• 行くべきだ
• 勉強するべきだ
• 注意すべきだ

When is べきだ used?

Use べきだ in situations like:

• giving strong advice
• discussing social obligations
• stating principles or rules

Tone and register:

• neutral to formal
• Common in giving strong advice, test questions, and written narratives

べきだ example sentences

• 自分の意見をはっきり言うべきだ。 — You should state your opinion clearly.
• 親の言うことを聞くべきだ。 — You should listen to what your parents say.
• 約束は守るべきだ。 — You should keep your promises.
• もっと早く家を出るべきだった。 — I should have left home earlier.
• 環境問題についてもっと考えるべきだ。 — We should think more about environmental issues.

Nuance of べきだ

The key nuance is carries a sense of moral or social obligation; heavier and more prescriptive than lighter suggestion patterns.

This matters because 〜べきだ feels definitive. It comes across as principled advice rather than a gentle suggestion. It is often what you ‘should’ do based on social norms, ethics, or logic.

For example:

• In giving strong advice, it sounds natural and specific.
• Compared with ばいい, it carries a different weight and implication.

べきだ vs ばいい

Both べきだ and ばいい can express should do, but they are different.

べきだ:

• stronger; implies moral or social obligation; sounds more definitive and judgmental

ばいい:

• softer suggestion; implies it would be good if, without the weight of obligation

Quick contrast examples:

• もっと勉強するべきだ。 — You should study more (it’s your duty).
• もっと勉強すればいい。 — You should study more (friendly suggestion).

Common mistakes with べきだ

Watch out for these mistakes:

• Using するべきだ vs すべきだ — both are correct, but すべきだ is slightly more formal
• Using it for light suggestions where ばいい or たらいい is better
• Confusing with べきだった (should have done / past form)

Is べきだ on the JLPT?

Yes. べきだ is commonly taught as JLPT N3 grammar.

That means learners should be able to:

• recognize it in reading
• understand its nuance in context
• use it in simple original sentences

Practice questions for べきだ

• Say someone should keep their promises.
• Advise someone to state their opinion.
• Talk about what society should do.

Learning path for べきだ

To learn べきだ efficiently, review simple must/cannot expressions first, then separate personal advice from social or practical pressure.

1. First, make sure you can form べきだ without looking at the pattern chart.
2. Next, compare it with ばいい, べきではない.
3. Finally, write situations involving work, promises, rules, or responsibility; then check whether replacing べきだ with しかない changes the meaning.

Related grammar to review next

• ばいい — should; can; it’d be good if.
• べきではない — should not do; must not do.
• しかない — have no choice but.
• わけにはいかない — cannot afford to; must not.

Learn べきだ with Hane

If you want to review べきだ together with the related patterns above, Hane helps you connect grammar, kanji, and vocabulary in short, focused sessions.

Browse more lessons here:

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• JLPT N3 grammar lessons