【问】 He ran away from school. He ought to have known better.请问句中的know better是什么意思?应如何翻译?

【答】 know better一般可理解为know better than to do sth.的省略形式。因此，上面的句子…have known better可以理解为…have known better than to run away from school(to doso)。全句似可译为：他逃学了。他本应该懂得不该这么做的(他本应该更懂事一些的)。(参见know better than to do)

有时候，know better是一个独立的用语，而并非是know better than to do的省略形式：

The experts，who knew better，laughed at the idea. (EED)

专家们更加敏锐，嘲笑了这种想法。