ならいざしらず / はいざしらず

ならいざしらず / はいざしらず means I don’t know about … but; it may be possible for … but ~. It is a JLPT N1 Japanese grammar pattern used to draw a sharp contrast by setting aside one case as possibly excusable or uncertain, in order to highlight that another case is definitely not, or that the speaker’s judgment is absolute.

This grammar point often appears in formal writing, editorials, debates, and JLPT N1 reading passages. If you want to strongly distinguish between two situations — one you’ll grant, the other you won’t — ならいざしらず / はいざしらず is a useful pattern to learn because it adds natural precision to your Japanese.

What does ならいざしらず / はいざしらず mean?

Use ならいざしらず / はいざしらず when you want to draw a sharp contrast by setting aside one case as possibly excusable or uncertain, in order to highlight that another case is definitely not, or that the speaker’s judgment is absolute.

Natural translations include:

• I don’t know about … but; I might accept … but; it’s one thing if … but; for … it may be possible, but ~

The best translation depends on the sentence. Try to notice the writer’s or speaker’s purpose first — are they dismissing the first part to emphasize the second? — then choose the English phrase that fits that context.

How to form ならいざしらず / はいざしらず

Examples of the pattern:

• 彼かれならいざしらず
• 子供こどもならいざしらず
• 一度いちどや二度(にど)ならいざしらず
• 新入しんにゅう社員しゃいんはいざしらず
• 安やすいものはいざしらず

The form before the grammar point matters. In JLPT questions, the wrong answer choices often use a similar meaning but attach it to the wrong type of word.

When is ならいざしらず / はいざしらず used?

Use ならいざしらず / はいざしらず in situations like:

• sharply contrasting two cases to emphasize the speaker’s judgment on the second
• acknowledging a hypothetical excuse only to reject it for the real situation
• criticizing or showing surprise when someone or something doesn’t meet a standard

Tone and register:

• often formal or written; can convey sarcasm, criticism, or strong subjective stance
• Common in test questions, essays, debates, news editorials, and JLPT N1 reading

ならいざしらず / はいざしらず example sentences

After reading each sentence, ask what job ならいざしらず / はいざしらず is doing: it sets aside a hypothetical situation to emphasize a real one. That makes the nuance easier to remember than a one-word translation.

Nuance of ならいざしらず / はいざしらず

The key nuance is sharp contrast between two cases, where the first case is granted hypothetical tolerance, while the second is definitively rejected or criticized.

This matters because learners often translate advanced grammar too literally. A pattern may look simple, but it can signal the writer’s attitude, the scope of a rule, or the relationship between two ideas.

For example:

• The phrase “いざしらず” itself comes from “いざ知ら(しら)ず” literally meaning “I don’t know about that,” so the speaker essentially says, “I won’t comment on case A (maybe it’s excusable), but case B is definitely out of the question.”
• Compared with simple なら (which just states a condition), ならいざしらず injects a strong value judgment and often an emotional charge — frustration, disappointment, or incredulity.

ならいざしらず / はいざしらず vs ならでは

Both ならいざしらず / はいざしらず and ならでは share the conditional なら, but they function very differently.

If both translations seem possible, check the tone. Is the speaker critical and dismissive, or complimentary and appreciative? The tone often tells you which grammar point is natural.

Common mistakes with ならいざしらず / はいざしらず

A helpful practice method is to write one sentence with ならいざしらず / はいざしらず, then rewrite it with なら. If the meaning or tone changes, explain that difference in your own words.

Is ならいざしらず / はいざしらず on the JLPT?

For test preparation, study the grammar point in full sentences. JLPT questions often test whether you understand the surrounding context, not just the dictionary meaning.

Practice questions for ならいざしらず / はいざしらず

Keep your first sentences simple. Once the structure feels natural, add more context so the nuance becomes clear.

Learning path for ならいざしらず / はいざしらず

To learn ならいざしらず / はいざしらず efficiently, start with its formation, then compare it with similar patterns, and finally practice in context.

Related grammar to review next

• ならでは — because it shares the conditional なら but flips the nuance from contrast to uniqueness
• なり — because it also expresses “as soon as” or “in one’s own way” and often appears in similar N1-level excerpts
• なり～なり — because it provides alternative suggestions, another form of contrastive thinking
• 何しろ(なにしろ) / 何(なん)にしろ — because it sets aside details to focus on a conclusion, much like いざしらず dismisses a hypothetical

Learn ならいざしらず / はいざしらず with Hane

If you want to review ならいざしらず / はいざしらず together with the related patterns above, Hane helps you practice Japanese in short, focused sessions.

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