Once you missed, you missed it forever.

一旦你错过了，你就永远错过了。

youdao

A species once extinct is gone forever.

一个物种一旦灭绝就永远消失了。

youdao

youdao

I have a friend who once claimed to me that he wanted to live forever so that he could have Thai food every day for the rest of, well, the rest of eternity.

一位朋友曾对我宣称,他希望永生以便在,以后无尽的日子里每天吃泰国菜。

耶鲁公开课 - 死亡课程节选

I had a roommate once who would leave her food out forever

我曾经有一个室友，她总把吃的东西放在外面，

布鲁克林的房价 - SpeakingMax英语口语达人

To be loved, baby, hard, at once, and forever, to strengthen you against the loveless world.

NPR: An Author's Companion in Rage, Exile and Return

Money once borrowed is forever borrowed.

FORBES: We'd All Better Hope Krugman Is Right On The U.S. Debt

Listen to it once, and it is forever seared in your mind.

FORBES: Alec Baldwin's Anger Management