他这么年轻就已经当上了英语系的副教授。

[误] Young as he is, he has become a vice-professor in English department.

[正] Young as he is, he has become an associate professor in English department.

注：许多人都知道“副总统”叫 vice-president，于是想当然地以为“副教授”就应该是 vice-professor，其实不对。“副”和 vice- 并不总是一一对应的，又如：副产品(by production)，副业(side occupation)，副作用(by-effect)等。