〜ならいざしらず / 〜はいざしらず
naraizashirazu-haizashirazu
By Nihongo PathUpdated
Meaning
X might be one thing, but …; I don't know about X, but …
Xならいざしらず / はいざしらず sets aside a case X where something would be understandable, and then says the present case is different and not acceptable or is surprising: 子供ならいざしらず、大人が泣くなんて. いざしらず literally means "I don't know (about that)".
Both registers, slightly old-fashioned and emphatic. Common in criticism and expressions of surprise. The second clause often ends with なんて / とは / 信じられない.
Formation
V = verb, N = noun, A = adjective.
Noun + ならいざしらずNoun + はいざしらず (topic form: 昔はいざしらず)Plain form + (の)ならいざしらずFollowed by a contrasting, criticised or surprising case
Visual diagram
| Aspect | case set aside | present case | tone |
|---|---|---|---|
| 子供ならいざしらず | a child (excusable) | an adult crying | criticism / surprise |
| 昔はいざしらず | the past (unknown) | now it is safe | contrast of times |
| 初心者ならいざしらず | a beginner (excusable) | a veteran's mistake | disbelief |
Natural examples
子供ならいざしらず、大人がそんなことで泣くなんて。
こどもならいざしらず、おとながそんなことでなくなんて。
A child might be one thing, but for an adult to cry over that...
Excusable case (child) vs criticised case (adult).
昔はいざしらず、今ではこの辺りも安全になった。
むかしはいざしらず、いまではこのあたりもあんぜんになった。
I cannot speak for the past, but nowadays this area has become safe.
Contrast of times with はいざしらず.
初心者ならいざしらず、ベテランがこんなミスをするとは信じられない。
しょしんしゃならいざしらず、ベテランがこんなミスをするとはしんじられない。
A beginner is one thing, but I cannot believe a veteran would make such a mistake.
Beginner vs veteran: disbelief with とは.
無料ならいざしらず、お金を払ってこのサービスでは納得できない。
むりょうならいざしらず、おかねをはらってこのサービスではなっとくできない。
If it were free that would be one thing, but paying for this service is unacceptable.
Complaint about value.
一度や二度ならいざしらず、毎回遅刻するのは問題だ。
いちどやにどならいざしらず、まいかいちこくするのはもんだいだ。
Once or twice might be forgivable, but being late every time is a problem.
Frequency contrast.
Similar grammar and the difference
Everyday equivalent: 子供ならともかく. いざしらず is more emphatic and literary. Compare side by side
"X would still be acceptable, but…": very close in meaning, spoken. Compare side by side
"It's not as if you are X": rules out X and scolds; いざしらず sets X aside as acceptable. Compare side by side
Common mistakes
- ✗
- 大人ならいざしらず、子供が泣くのは当然だ。
- ✓
- 子供ならいざしらず、大人が泣くなんて。
- Why
- The excusable case comes first; the criticised case follows.
- ✗
- 子供ならいざしらず、子供が泣いた。
- ✓
- 子供ならいざしらず、大人が泣くとは驚きだ。
- Why
- The second clause must be a different, contrasting case.
- ✗
- 子供はいざしらずなら
- ✓
- 子供ならいざしらず / 子供はいざしらず
- Why
- Use either なら or は, not both.
いざ知らず is also written with kanji. Typical endings: なんて, とは, 信じられない, 問題だ, 許されない. はいざしらず is common with time or place nouns: 昔は, 外国は, 都会は.
JLPT N1 tips
On the exam
- An excusable case + blank + a criticised different case ending in なんて / とは → ならいざしらず.
- Distractors ならともかく and ならまだしも mean the same; if all three are offered, the exam usually uses a different structure for the others, so check the endings and the register.
- はいざしらず appears with 昔 / 外国 / 他の人; look for a contrast of times or places.
Frequently asked questions
What does 〜ならいざしらず / 〜はいざしらず mean?
X might be one thing, but …; I don't know about X, but …. Xならいざしらず / はいざしらず sets aside a case X where something would be understandable, and then says the present case is different and not acceptable or is surprising: 子供ならいざしらず、大人が泣くなんて. いざしらず literally means "I don't know (about that)".
How do you form 〜ならいざしらず / 〜はいざしらず?
Noun + ならいざしらず / Noun + はいざしらず (topic form: 昔はいざしらず) / Plain form + (の)ならいざしらず / Followed by a contrasting, criticised or surprising case. V = verb, N = noun, A = adjective.
When is 〜ならいざしらず / 〜はいざしらず used?
Both registers, slightly old-fashioned and emphatic. Common in criticism and expressions of surprise. The second clause often ends with なんて / とは / 信じられない.
What is the difference between 〜ならいざしらず / 〜はいざしらず and 〜ならともかく?
Everyday equivalent: 子供ならともかく. いざしらず is more emphatic and literary.
What is the difference between 〜ならいざしらず / 〜はいざしらず and 〜ならまだしも?
"X would still be acceptable, but…": very close in meaning, spoken.
What is a common mistake with 〜ならいざしらず / 〜はいざしらず?
Wrong: 大人ならいざしらず、子供が泣くのは当然だ。 Right: 子供ならいざしらず、大人が泣くなんて。 The excusable case comes first; the criticised case follows.
Quick check
新人（ ）、十年目の社員がこんな初歩的なミスをするとは。