He has that je ne sais quoi that distinguishes a professional from an amateur.

他有那种难以言表的特质，体现出他是专业而非业余的。

《牛津词典》

I have learned many languages, but I've not mastered them the way a professional interpreter or translator has.

我学过许多语言，但我还没有像专业的翻译人员那样精通这些语言。

youdao

youdao

We're trying to run a school here that has some professional standards.

我们试图运行一个学校,里面有些专业的标准。

麻省理工公开课 - 固态化学导论课程节选

Perfect for any Hollywood type, the estate has a professional theater with a wet bar and plenty of seating.

FORBES: DreamWorks CEO Jeffrey Katzenberg Lists Beverly Hills Mansion

The 58-year-old, who has a professional food-service background, consulted the two brothers who founded NYPD and helped them open a second location.

WSJ: How 3 Small Firms Are Coping With Health Law

This, together with ongoing efforts by The Lehrman Institute and by its strategic partner, the American Principles Project (with both of which this writer has a professional association) laid the groundwork for another critical development: putting monetary reform at the core of the agenda of the conservative movement.

FORBES: The Death Certificate Of The Paper Dollar: Where To Next?