べきだ

べきだ
expression
should; ought to; must
1. should; ought to
Expresses a moral obligation, recommendation, or the speaker's judgment that something is the right or proper course of action.
もっと勉強(べんきょう)するべきだ。
You should study more.
約束(やくそく)(まも)るべきだ。
One should keep one's promises.
自分(じぶん)意見(いけん)をはっきり()うべきだと(おも)う。
I think you should state your opinion clearly.
2. should have; ought to have
Used in the past tense (べきだった) to express regret or criticism that something was not done when it should have been.
もっと(はや)相談(そうだん)するべきだった。
I should have consulted earlier.
(かれ)(あやま)るべきだった。
I should have apologized to him.
あの(とき)医者(いしゃ)()くべきだったと後悔(こうかい)している。
I regret that I should have gone to the doctor at that time.

Attaches to the dictionary form of verbs. Expresses the speaker's judgment about what is proper, right, or advisable. Stronger than ほうがいい and carries a tone of moral or logical imperative.

COMMON PATTERNS:

  • verb dictionary form + べきだ: ()くべきだ (should go)
  • するべきだ / すべきだ: both forms are used (すべき is more formal)
  • べきではない: should not
  • べきだった: should have (past regret)
  • べきではなかった: should not have

SIMILAR EXPRESSIONS:

  • はずだ: expresses expectation or logical conclusion ("should" as in "is expected to"), while べきだ expresses obligation or recommendation
  • ほうがいい: a softer recommendation ("it would be better to"), while べきだ is a stronger, more principled assertion
  • なければならない: expresses necessity or compulsion ("must"), while べきだ is more about what is right or advisable

REGISTER:
Slightly formal in tone. Common in written Japanese, editorials, and when giving advice. The polite form べきです is used in conversation.