中文原文：

我们必须分清是非界限。

错误译文：

We must make a clean break between right and wrong.

正确译文：

1) We must distinguish between right and wrong.

2) We must discern between right and wrong.

3) We must draw a clear distinction between right and wrong.

4) We must tell right from wrong.

5) We must tell between right and wrong.

6) We must know the right from the wrong.

翻译加油站：

to make a clean break 的意思是to make a complete separation，后跟介词from 或with，即“与……彻底决裂”。例如 He wants to make a clean break with the past.(他要与过去彻底决裂。) 这个动词短语后面不能跟介词between引导的短语。

“界限”表达的是抽象概念，它的第一个意思是“不同事物的分界”，英语可以译为 bounds, limits, 例如：

1. 界限分明。The bounds/limits are obvious.

2.这个科研项目要打破一些学科界限。This scientific research project entails breaking the bounds among several academic disciplines.

“界限”的第二个意思是“对立事物的分界”，经常用一对反义词作为“分清”、“划清”和“混淆”的宾语。而且常常省略“界限”一词。英语可以译为 dividing line,例如：

3. 他的讲话混淆了是非界限/混淆了是非。His speech confused (the dividing line between) right and wrong

“界限”的第三个意思是“限度”、“尽头”、“止境”，英语可以译为limit。例如：

4. 他的贪欲是没有界限的。His greed knows no limit.