べからず
Do not, Must not, Should not, Cannot (べからざる)
Structure
Exceptions:
する ￫ す(1) + べからず
Verb + べからざる + Noun
which is generally limited to:
許すべからざる + Noun
ありうべからざる + Noun
欠くべからざる + Noun
(1) する
Explanation
べからず and べからざる are formal grammar patterns that express a strong prohibition, equivalent to 'must not do (A)' or 'should not do (A)'. They are formed from the helper-conjugation form of the auxiliary verb べし, which is べから, and the classical auxiliary verb for negation, ず. Since ざる is simply the helper-conjugation form of ず, the meaning is identical. This structure retains the nuance of moral or logical imperative seen in all grammar points derived from べき.
Both べからず and べからざる are attached to the dictionary form of a verb. The form べからざる is used specifically to modify a noun that immediately follows it.
- ことわざ：「人の陰口を言うべからず。」Proverb: 'One must not speak ill of others.'
- この図書館内では食べ物を持ち込むべからず。You must not bring food into this library.
- 他人の努力を笑うことは許すべからざる態度だ。Mocking the efforts of others is an unforgivable attitude.
- 触れるべからざる展示品に手を出したら、警備員に注意されるよ。If you try to touch an exhibit that you must not touch, you'll be warned by the security guard.
In modern-day Japanese, the nuance of these grammar patterns has moved away from 'obligation' and now carries a very strong sense of 'don't (A)'. Furthermore, they are almost exclusively encountered in writing, such as on signs and official notices.
Caution
The べからざる form used before a noun typically appears in a few fixed phrases. The most common are 許すべからざる 'unforgivable', ありうべからざる 'impossible', and 欠くべからざる 'indispensable'.
Examples
他人を傷つけることは許すべからざる行為だ。
Harming others is an unacceptable act. (an act that must not be forgiven)
図書館の掲示：「館内にて大声で話すべからず」
Notice in a library: 'Do not speak loudly inside the library'
会社の機密情報は外部に漏らすべからず。
You must not leak confidential company information to outsiders.
崖の近くの看板：「この先、危険につき立ち入るべからず」
Sign near a cliff: 'Danger ahead. Do not enter'
記事の見出し：「初デートで成功するための『べし・べからず』」
Article headline: 'The Dos and Don'ts for a successful first date.'
チームワークはプロジェクトの成功に欠くべからざる要素だ。
Teamwork is an indispensable element for the project's success. (An element that must not be lacking)
武士の掟：「主君への忠義を怠るべからず」
Samurai code: 'One must not neglect loyalty to one's lord.'
寺の聖域への立ち入り口の看板：「関係者以外入るべからず」
Sign at the entrance to a temple's sacred area: 'Authorized personnel only. Do not enter'
人の信頼を裏切るべからず。それは何よりも重い罪だ。
You should not betray someone's trust. It is a heavier sin than anything else.
小説より：「彼は私の家族に対して、許すべからざる侮辱を与えた。」
From a novel: 'He directed an unforgivable insult at my family.' (an insult that cannot be forgiven)
競技のルール：「審判の判定に異議を唱えるべからず」
Competition rules: 'One must not dispute the referee's decision.'
先生が生徒に：「学問の道に近道なし、と言う。日々の努力を怠るべからず。」
Teacher to student: 'They say there are no shortcuts on the path of learning. You must not neglect your daily efforts.'