Once a beggar, always a beggar.一次做乞丐，永远是乞丐。

Once a devil, always a devil.一次做魔鬼，永远是魔鬼.

Once a knave¹, ever a knave.一朝失足，铸成千古恨.

Once a man and twice a child.一次为成人，两度当小孩.

Once a thief, always a thief.偷盗一次，做贼一世。

Once bit, twice shy.一朝被蛇咬，三年怕草绳.

Once bitten, twice shy.一朝被蛇咬，十年怕井绳。

Once is no custom.一次不成例.

Once on shore, we pray no more.一旦上了岸，就不再祈祷.

One barking dog sets all street a-barking.一狗吠声响，狗吠满街坊.

One beats the bush, and another catches the birds.坐享其成.

One boy is a boy, two boys half a boy, three boys no boy.一个和尚挑水喝，两个和尚抬水喝，三个和尚没水喝。

One boy is more trouble than a dozen girls.一个男孩比十二个女孩还要麻烦.

One cannot always be a hero, but one can always be a man.人难一世称雄，但可一生为人.

One cannot do a foolish thing once in one's life, but one must hear of it a hundred times.为人一生一件蠢事也不做，但要听到上百遍蠢事.

One cannot eat one's cake and have it.事难两全其美.

One cannot get blood from a stone.石头里抽不出血.

One cannot make a silk purse out of a sow's ear.朽木不可雕.

One cannot make bricks without straw.巧妇难为无米之炊.

One cannot put back the clock.光阴一去不复返.

"One cannot put back the clock.

"时光不能倒流。

One chick keeps a hen busy.一只小鸡已够母鸡辛忙.

One cloud is enough to eclipse all the sun.一叶可障目.

One crowded hour of glorious life is worth an age without a name.光辉生活中忙迫的一个小时抵得上无为的一世.

One drop of poison infects the whole tun of wine.一滴之毒，毒染整桶之酒.

One enemy can do more hurt than ten friends can do good.十个朋友做的好事抵不上一个敌人造成的危害.