～さえ
even
～さえ attaches to a noun to single it out as an extreme example: “even X”. If even X is true (or not true), everything less extreme goes without saying. It replaces が and を, and follows other particles (にさえ, でさえ).
The particle も can also mean “even”, but さえ is more emphatic and deliberately picks the most extreme case. In the pattern さえ～ば, it instead marks the one and only condition needed: “as long as / if only”.
1. Extreme example: “even X”
Often used with negatives: not even the most basic thing is possible, so the rest certainly is not.
あの子は自分の名前さえ書けない。
“That child can't even write his own name.”
- あの子（あのこ）= that child
- は = topic marker
- 自分（じぶん）= one's own
- の = possessive marker
- 名前（なまえ）= name
- さえ = even
- 書けない（かけない）= cannot write
2. Sole condition: さえ～ば
Combined with the ば-form, さえ means that this one condition is all it takes, nothing else matters.
時間さえあれば、もっと勉強できるのに。
“If only I had time, I could study more.”
- 時間（じかん）= time
- さえ = (if) only / as long as
- あれば = if there is
- もっと = more
- 勉強できる（べんきょうできる）= can study
- のに = and yet (regret marker)
How to form it
Noun + さえ (replacing が/を); for the condition, Noun + さえ + verb ば-form
- 名前（なまえ）= name → 名前さえ（なまえさえ）= even (one's) name
- 水（みず）= water → 水さえ飲めない（みずさえのめない）= can't even drink water
- 時間がある（じかんがある）= to have time → 時間さえあれば（じかんさえあれば）= as long as there is time
Key idea
さえ points at the bottom line. As “even”, it says the most extreme case holds, so everything else follows. As さえ～ば, it says this one thing is all you need.
Other N3 grammar
Updated .