すればよかった

should have done

→ 為る
phrase Rare #35,789
should have done Expresses regret or criticism about something that was not done. The subject and object are usually understood from context.
JA: もっと早くに出発すればよかった。
EN: I should have left earlier.

別の男性と結婚すればよかったのになあ。

I wish I had married a different man.

もっと早くに出発すればよかった。

I should have left earlier.

用心すればよかった

I should have been more careful.

— ミッション・クレオパトラ (2002)

君は彼の計画を採用すればよかったのだ。

You should have adopted his plan.

君はもっと健康に注意すればよかった。

You should have taken better care of your health.