べくもない means cannot possibly be; there’s no way that…. It is a JLPT N1 Japanese grammar pattern used to negate an action or state based on what should be possible or expected — highlighting that something is utterly impossible given the circumstances.
This grammar point often appears in formal writing, literary commentary, news analysis, and JLPT N1 reading passages. If you want to express that something simply cannot happen, even though it might be expected, べくもない is a precise and emphatic tool.
What does べくもない mean?
Use べくもない when you want to say that a certain result or action is entirely unattainable — not because of a specific prohibition, but because reality makes it impossible. The pattern carries a sense of should be possible, yet isn’t.
Natural translations include:
- cannot possibly be ; there is no way that … ; it is not possible to …
The right English choice depends on the verb in question (know, compare, reach, etc.) and the tone of the sentence.
How to form べくもない
- 知る（しる）→ 知るべくもない
- 比べる（くらべる）→ 比べるべくもない
- 及ぶ（およぶ）→ 及ぶべくもない
This pattern is frozen: you never add だ or adjust ない. The べく part is the adverbial form of the classical auxiliary べし, and the whole phrase is treated as a predicate adjective phrase. It’s almost always used as a sentence-ending predicate or to modify a noun (e.g., 知るべくもない事実).
In JLPT questions, the wrong answer choices often give you べきもない or べからざる, so remember that only the く-form (べく) attaches to もない.
When is べくもない used?
Use べくもない in situations like:
- commenting that something cannot possibly be known, compared, achieved, etc.
- pointing out an obvious contradiction between expectation and reality
- delivering a sober, often resigned judgment in formal writing
Tone and register:
- formal, written, or solemn — rare in casual speech
- carries a weight of finality; the speaker has already concluded there is no way
You’ll see it in newspaper editorials, critical essays, and some historical fiction.
べくもない example sentences
After reading each sentence, notice the gap between what should be knowable and what is actually knowable. That’s the essence of べくもない.
Nuance of べくもない
The core nuance is impossibility rooted in the nature of the verb itself. It’s not just “can’t” — it’s “no matter what, it’s not in the cards”.
This differs from saying 知ることができない (I am unable to know) or 知るはずがない (it cannot be that I know). べくもない emphasizes that even the precondition for possibility is absent — the very act of knowing is out of reach, not just blocked by effort or chance.
べくもない vs はずがない
Both べくもない and はずがない express strong negation of a possibility, but their focus differs.
べくもない:
- impossibility rooted in the expected, “should be” nature of the verb
- often tied to verbs like know, compare, reach, describe
- tone: formal, weighty, final
はずがない:
- general “cannot be the case” based on logical reasoning
- applies to any situation, person, or event
- tone: argumentative, everyday
Choose べくもない when you want to close the door on possibility with a tone of finality. Stick with はずがない when you’re simply pointing out a logical contradiction.
Common mistakes with べくもない
A good rule: if you can replace “cannot possibly” with “there’s no way to [verb]”, and the verb is something like know, compare, reach, or describe, べくもない is likely a good fit.
Is べくもない on the JLPT?
Reading: you should recognize it in formal passages and know it means impossibility.
Grammar: might appear in the sentence-structure section, often together with other classical auxiliaries like べく or べからず.
Usage: not typically required in production, but knowing the pattern helps you parse complex N1 texts.
Even if you don’t need to write it, understanding べくもない saves time when you encounter it in the Reading section. Look for the “dictionary form + べくもない” cluster and mentally replace it with “cannot possibly be ~”.
Practice questions for べくもない
Keep your sentences formal and written-style. Adding a context like a historical article or critical review will make the pattern feel natural.
Learning path for べくもない
Related grammar to review next
- べく — positive adverbial form “in order to; should”
- べくして — “as expected; destined to”
- びる・びて・びた — classical suffix giving a “seems like” nuance
- べからず・べからざる — strong prohibition “must not; cannot be allowed”
Learn べくもない with Hane
If you want to review べくもない together with the related classical patterns above, Hane helps you practice Japanese in short, focused sessions.
Browse more lessons here:
FAQ about べくもない
What does べくもない mean in Japanese?
べくもない means “cannot possibly be” in Japanese. It is an N1 grammar point, and this lesson explains its formation, nuance, example sentences, common mistakes, and similar grammar.
Is べくもない on the JLPT?
べくもない is taught as N1 Japanese grammar in Hane's grammar lesson archive. Review it with examples, usage notes, and related N1 patterns.
How should I practice べくもない?
Read several example sentences, identify the form before and after べくもない, then make your own short sentences and compare it with nearby grammar points.