べし

Freq.FrequencyTop 10,000

Meanings

auxiliary, ku-adjective (archaic)

formal or literaryusually written using kana alone

Formal/literary auxiliary expressing strong obligation or expectation. In modern Japanese, べき is the more common equivalent. Used primarily in writing or set phrases.

Usage patterns

〈動どう詞し〉べしshould/must/will surely do ~ (classical, formal)
汝なんじ、己おのれを知しるべし。
One should know oneself.

Kanji

可can, passable, approval

Related words

べき sense 1
べき is the standard modern equivalent of べし for expressing obligation, while べし is archaic/literary and mainly found in set phrases or classical texts.
なければならない sense 1
なければならない is the common everyday way to say 'must' in modern Japanese, whereas べし is formal/literary and rarely used in ordinary conversation.

Opposites

べからず sense 1
べからず is the negative classical form meaning 'must not / shall not', the direct opposite of the obligation sense of べし.

Written forms

べしUsage100%
Standard modern kana spelling for this classical auxiliary. The kanji form 可し is rare and archaic.
可べしUsage<1%
rarely-used kanji form
Rare kanji form; almost never used in modern Japanese. Included for recognition of classical texts.
ベシUsage<1%

Etymology

Classical Japanese auxiliary verb. The exact derivation is uncertain, but it has been used since Old Japanese to express obligation, certainty, and volition.