薮下研究室

■もし今水がなければ、僕らは生きてはゆけないだろう。
If we did not have water, we could not live.
＝If it were not for water, we could not live.
＝Were it not for water, we could not live.
＝Without water, we could not live.
＝But for water, we could not live.

If it were not forの「for」は「理由のfor」です。これは、前に「比較」のところやったall the better forの「for」と同じです。for Aで「Ａが理由で」「Ａのために」「Ａのお陰で」でしたね。
▼僕は昼寝をしたお陰でだいぶん気分が良くなった。
I took a nap after lunch and felt all the better for it.
だからIf it were not forＡは「もし今の状況がＡの恩恵を受ける（お陰を被る）ことがなければ」が元々の意味で、それが「もしＡがなければ」で使えるわけですね。

But forＡの「but」は「以外のbut」です。
▼水以外には何もなかった。
There was nothing but water.
だから、But forＡは「Ａの恩恵を受ける以外は」が元々の意味で、それが「Ａがなければ」で使えるわけです。さて、「あの時なかったら」にするには昔を悔やむときはhad＋過去分詞で悔やめ」だから、こうなります。

■もしあの時水がなかったら、僕らは生きてはゆけなかっただろう。
If we hadn’t had water, we could not have lived.
＝If it had not been for water, we could not have lived.
＝Had it not been for water, we could not have lived.
＝Without water, we could not have lived.
＝But for water, we could not have lived.

さて、もうちょっと問題を難しくしたければ、こうします。青いのが「現実時間」、赤いのが「妄想時間」の仮定法なので注意してください。
■水のお陰で、僕らは生きのびることができた。
Thanks [Owing / Due] to water, I could live.
＝On account of water, we could live.
＝Because of water, we could live.
＝If it had not been for water, we could not have lived.
＝Had it not been for water, we could not have lived.
＝Without water, we could not have lived.
＝But for water, we could not have lived.

【第３０章 仮定法（３）】例文＝２４９
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