[Serie: All About Japanese Particles]
Note: This usage is similar to de mo (#5, no. 2), but is more emphatic.
その問題は先生でさえ答えられなかった。
Sono mondai wa sensei de sae kotaerarenakatta.
Even the teacher couldn’t answer that [test] question.
そんな簡単なことは、子供でさえ知っていますよ。
Sonna kantan na koto wa, kodomo de sae shitte imasu yo.
Even a child knows such a simple thing! / A mere child would know something as simple as that.
2. In the form sae … -tara or sae … -ba, implies that if something additional is (had been) done, a positive outcome will occur (would have accurred): “if only.”
もう5分さえあったら、飛行機に間に合ったのに…
Mō gofun sae attara, hikō-ki ni ma ni atta no ni…
If we had only five more minutes, we would have been on time for the flight.
健ちゃんは頭がいいんですから、勉強さえすればいい大学に入れますよ。
Ken-chan wa atama ga ii-n desu kara, benkyō sae sureba ii daigaku ni hairemasu yo.
Ken has a good head on his shoulders, so if he only studies, he’ll be able to get into a good university.
– Source: All about particles – A handbook of Japanese function words –
