翻译keep doing和keep on doing，并解释它们有什么区别。

感情色彩的程度不一样,前者语气稍弱,后者有历经困难还要坚持的意思,但基本上可以代换,英语不能钻牛角尖.

一直做某事，继续做某事

语境不一样

For five years, our Party has been overcoming them gradually and with the utmost effort; our slogan is to strengthen unity, and we must keep on doing so.
五年以来，我党用了极大的力量逐步地克服着这个困难，我们的口号是增强团结，今后还要增强它。

Tired as she was, she kept doing it.
她虽然累了，仍继续做下去。