今更悔やんでも後の祭りだ。

tbd

It is too late to repent.

今更そんなことを言った日にゃ、火に油を注ぐことになるだけだよ。

tbd

For you to come out and say that kind of thing now would just be pouring oil on the fire.

你現在說這種話，只會火上加油。

今さら騒いでもどうにもならないよ。後の祭りだよ。

tbd

Yelling about it won't help now. You should have done that when it counted.

経験のあるもののほうがない者よりも役に立つのはいまさら言うまでもない。

tbd

It is needless to say that an experienced person will do better than someone without experience.

ここまで計画したのに、今更やめるって言わないでよ。

tbd

Don't tell me you're going to back out after all the plans we've made.

いまさら遅いよ。

tbd

It's too late now.

いまさら嘆いても、それこそ、後の祭だよ。

tbd

You can regret it all you want, but it won't do you any good now.

いまさら焦っても焼け石に水じゃないの。

tbd

No matter how much you hurry your effort is just a drop in the bucket.

今更後悔しても無駄だ。

tbd

It's no use regretting it now.

いまさらあの事故のことで彼を非難しても仕方ない。

tbd

It is no use blaming him for the accident now.