のではないか details
write + isn't it that…? — a guess offered as a question instead of asserted
kaku no de wa nai ka
isn't it that…? — a guess offered as a question instead of asserted
あの店、今日は休みなんじゃない？
ano mise, kyou wa yasumi na n ja nai?
That shop's closed today, isn't it? casual
失敗するのではないかと不安で、なかなか眠れなかった。
shippai suru no de wa nai ka to fuan de, nakanaka nemurenakatta.
I was so uneasy that I might fail, I could hardly sleep. neutral
- dictionary form
- past
- negative
- negative + past
- na-adjective
- noun
- contraction
- alternant
- formal
- alternant
- polite
Examples
isn't it that…? — the speaker puts a conclusion forward as a question, expecting the listener to come round to it
あの店、今日は休みなんじゃない？
ano mise, kyou wa yasumi na n ja nai?
That shop's closed today, isn't it? casual
このやり方では、かえって時間がかかるのではないか。
kono yarikata de wa, kaette jikan ga kakaru no de wa nai ka.
Won't this way actually take longer? neutral
便利さを求めすぎた結果、大切なものを失ったのではないだろうか。
benrisa o motomesugita kekka, taisetsu na mono o ushinatta no de wa nai darou ka.
In chasing convenience so hard, have we not lost something that mattered? neutral
本件につきましては、いま一度ご検討いただく必要があるのではないでしょうか。
honken ni tsukimashite wa, ima ichido go kentou itadaku hitsuyou ga aru no de wa nai deshou ka.
On this matter, is there not a need for you to give it further consideration? formal
the thing the speaker is afraid might be so — the clause sits under と with 心配[しんぱい]だ, 不安[ふあん]だ or 気[き]がする
失敗するのではないかと不安で、なかなか眠れなかった。
shippai suru no de wa nai ka to fuan de, nakanaka nemurenakatta.
I was so uneasy that I might fail, I could hardly sleep. neutral
忘れられてるんじゃないかって、ちょっと心配になった。
wasurerareteru n ja nai ka tte, chotto shinpai ni natta.
I started worrying a bit that they'd forgotten about me. casual
Formation
{P}のではないかattaches to plain form{NA-stem}なのではないかattaches to na-adjective{N}なのではないかattaches to noun
Variant notes
- んじゃないか — の→ん and では→じゃ, the spoken default — 間違えたんじゃないか。Question-final んじゃない？ is the same thing with the か left to intonation.
- のではないだろうか — だろう softens it further and is the shape written argument reaches for — 私たちは急ぎすぎたのではないだろうか。
- のではありませんか — not merely a politer のではないでしょうか — it presses, and is used to put a point to someone who ought to concede it (お約束と違うのではありませんか).
- のでは — the tail trails off and ないか is left unsaid — それでは間に合わないのでは… Softer than finishing the sentence; a spoken hedge above all, and in writing it is normally completed (〜のではないかと存じます).
Notes
元気なのではないか. Bare 学生ではないか is a different
sentence altogether: "why, he's a student!"
Related patterns
Similar
だろう states the guess and stands behind it (古すぎるだろう); のではないか hands it over as a question and leaves the listener room to say no, which is why an argument closes on のではないでしょうか rather than on だろう.
かもしれない rates the guess as merely possible and invites no response; sentence-final のではないか rates it as likely and angles for agreement — 遅れるかもしれない warns, 遅れるのではないか asks you to admit it.
Lookalikes
Same のではない, and か decides whether the ない is asserted or offered — without it the sentence denies the explanation the listener assumed (買ったのではない、作ったのだ), with it the same string floats a guess (買ったのではないか, "isn't it that they bought it?"); in speech only the intonation separates them.
ではないか takes its reading from what sits in front of it — a volitional stem makes it a rallying call (やろうではないか), the nominalizer の makes it this hedge (やるのではないか), and a bare noun makes it neither of the two (学生ではないか is "why, he's a student!").