请教大师“屡败屡战”用英语咋说?

suffer repeated defeats but keep on fighting.

首先申明我不是大师。不过你的句子有个问题,你发现没呀？没主语,这可不行！试改：Even if we suffer repeated defeats, we keep on fighting.

We never gave up: the more we lost，the harder we fought back.

如果不要那么斗志昂扬的话，也已照字面译：

Whenever we lost, we just fought back.

不过我您愿相信第一种译法更贴近曾国藩的愿意与人格。