You should teach him a lesson.是什么意思？

You should teach him a lesson.

你应该教训他一顿。

you

pron. 你，你们，您们，各位，大家；

例句
I suggest you leave it to an expert...
我建议你把它留给专家来解决。

should

应该，将会，可能，本应；

例句
The older child should be able to prepare a simple meal...
那个年纪稍大的孩子应当会做一顿简单的饭菜。

teach

vt. 教，教导，训练，教授；vi. 教书；

例句
Different schools teach different types of syllabus, from the highly academic to the broadly vocational.
不同的学校有不同的教学计划，从高度学术的到普通职业教育的，不一而足。

him

pron. (he的宾格)他；

例句
They said goodbye to him as he got aboard the train at Union Station.
当他在联合火车站登上火车之际，他们向他道别。

lesson

n. 教训，训诫，功课，课程，一堂课，[宗]日课；vt. 教训，训斥，教课，向…授课；

例句
Almost the first lesson they learn is how to dissociate emotion from reason.
如何将理智和情感分开几乎可以说是他们所上的第一课。