Noun ならいざ知らず

When to use

Formal, literary "X is one thing, but Y is another (less certain) matter".

Explanation

「Xならいざ知らず、Yは…」 emphasizes that while X might be possible or acceptable, Y is out of the question or even more difficult. It can be translated as 'I could understand X, but Y is impossible' or 'Maybe X, but definitely not Y.'

• 数学すうがくならいざ知しらず、物理ぶつりなんて全然ぜんぜんわからない。

  Math might be manageable, but as for physics, I'm completely clueless.

  Suugaku nara iza shirazu, butsuri nante zenzen wakaranai.

• 5キロならいざ知しらず、10キロなんて走れません。

  Maybe I could run 5 kilometers, but 10 kilometers is out of the question.

  Go kiro nara iza shirazu, juu kiro nante hashiremasen.

• 日本語にほんごならいざ知しらず、中国語ちゅうごくごなんて話はなせない。

  I might be able to speak Japanese, but Chinese is impossible for me.

  Nihongo nara iza shirazu, chuugokugo nante hanasenai.

• 冷つめたい水みずならいざ知しらず、熱あつい水みずで泳およぐなんて考かんがえたこともない。

  Maybe cold water, but swimming in hot water never even crossed my mind.

  Tsumetai mizu nara iza shirazu, atsui mizu de oyogu nante kangaeta koto mo nai.

Setting Aside (X Aside / X Is One Thing, But)

• ～はともかく～は〜wa tomokaku 〜waN2Used to compare or contrast two elements; 'as for...'.
• ～はまだしも〜wa mada shimoN2Expresses that while the first item is somewhat…
• ～は抜きにして〜wa nuki ni shiteN2Leaving aside, excluding.
• Noun はさておき~ wa sateokiN1Means 'putting aside', 'aside from', 'notwithstanding'.

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