[Serie: All About Japanese Particles]
Note: Ni commnly follows darō, deshō, and V-tarō, and essentially has the same meaning as no ni (#30, no. 2), although the latter is more common.
1. Expresses regret that something is over and can’t be regained: “despite the fact that, if only.”
ほかの人がやったら、もっと早くできたでしょうに。
Hoka no hito ga yattara, motto hayaku dekita deshō ni.
Despite the fact that it could have been finished much sooner if someone else had done it, [unfortunately that was not the case]. / It could have been finished much sooner if only someone else had done it.
もう少し待っていたら、雨がやんだろうに。
Mō sukoshi matte itara, ame ga yandarō ni.
Despite the factt that if we had waited a little longer, the rain might have stopped [we didn’t wait]. / It only we had waited a little longer, the rain might have let up.
– Source: All about particles – A handbook of Japanese function words –
