But if one day you call.

但如果有一天你叫我。

youdao

But if one day you call, And there is no answer.

但是，如果一天你给我打电话却没有人回答。

youdao

It ought to mean "to go forward" with everything behind it, but needless to say her thoughts on the subject were never implemented because if one day red light means "stop" and the next day red light means "go," there might be a few problems.

它因该表示勇往直前，当然她的想法没有实现,因为如果红灯今天表示停,明天表示走，会天下大乱的。

耶鲁公开课 - 文学理论导论课程节选

All well and good, but what if, one distant day, the central bank decides to tighten monetary policy again by selling some of those bonds?

ECONOMIST: The Bank of Japan

He might still get it one day, but if he did, not all Norwegians would applaud.

ECONOMIST: Norway and terrorism

But if it loses any more ground, Bavarians may one day find that they have an opposition after all.

ECONOMIST: Bavarian politics