What it means
はおろか means “let alone” or “not to mention.” It presents the first item as an extreme or expected case and emphasizes that even a more basic, likely, or closely related case does not apply, or that an additional case is also true. The following clause commonly contains も, さえ, or すら to mark the emphasized comparison. This expression is generally used in formal writing, speeches, and carefully structured statements.
Usage note
はおろか is more formal and emphatic than ordinary “not to mention” expressions. It usually introduces an item that would normally be expected before adding a stronger or broader statement, so the relationship between the two items should be logically clear.
How to use it
彼女は国内旅行はおろか、近所への外出さえ控えています。
She refrains from going out even to places nearby, let alone taking domestic trips.
彼は研究を続けるのはおろか、会議に出席することさえ拒みました。
He refused even to attend the meeting, let alone continue his research.
彼女は国内旅行はおろか、近所への外出さえ控えている。
She refrains from going out even to places nearby, let alone taking domestic trips.
彼は研究を続けるのはおろか、会議に出席することさえ拒んだ。
He refused even to attend the meeting, let alone continue his research.
Example sentences
この論文は専門家はおろか、大学院生でさえ理解に時間を要するほど専門的だ。
This paper is so technical that it takes even graduate students, let alone experts, time to understand.
その村には、病院はおろか、診療所さえない。
That village does not even have a clinic, let alone a hospital.
その新人はおろか、経験豊富な社員でさえ操作方法