However, the specific context will determine the best translation:
* "Extraordinary exam" is a more literal translation and is used when referring to an exam taken outside of the regular exam period, usually for students who failed the regular exam.
* "Special exam" is a more general term that can be used for any exam that is not part of the regular curriculum, including exams for advanced placement or for students who need to catch up on missed material.
It's important to consider the context and the specific situation when translating "examen extraordinario."