Explanation
Expresses 'not to mention ~, even ~'.
Formation
Noun1 はおろか, Noun2 すら/さえ ～
Detailed explanation
The grammar point Noun はおろか～すら is used to emphasize that a particular statement applies not only to the first noun mentioned, but even more so to what comes after すら or さえ. It can be translated as ‘let alone ~, even ~’.
Examples
彼は走るはおろか、速く歩くことすらできない。
Kare wa hashiru wa oroka, hayaku aruku koto sura dekinai.
He can't even walk fast, let alone run.
日本語はおろか、英語さえ話しません。
Nihongo wa oroka, eigo sae hanashimasen.
He doesn't even speak English, let alone Japanese.
彼は食事はおろか、一日中何も飲まなかった。
Kare wa shokuji wa oroka, ichinichijuu nani mo nomanakatta.
He didn't even drink anything all day, let alone eat a meal.
このレストランは味はおろか、サービスさえ悪い。
Kono resutoran wa aji wa oroka, saabisu sae warui.
Never mind the taste; even the service is bad.
Practice
Grammar content sourced from hanabira.org.