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》

Although the "ne" in negatives should always be written, it is very rarely used in informal speech.

尽管“ne”在否定式中应总被书写，在非正式口语中却很少被用到。

youdao

For those of you who have never heard French before, when you hear somebody say, "Je ne sais pas," you could say, "Remarkable!"

对于你们那些从未听过法语的人来说，当你们听到有人说“Je ne sais pas”，你可能会说：“太神奇了！”

youdao

Then he read about a famous French magician named Jean Eugne Robert-Houdin.

VOA: special.2010.12.19

And you-- And now a French speaker, of course, hears "Je ne sais pas."

当然,讲法语的人听到"我不知道"时,是会感觉到停顿的

耶鲁公开课 - 心理学导论课程节选

On this album,you know, Ne-Yo and Tricky and The-Dream and Kuk and The Movement and Akon, I'm telling you this album is amazing,"

VOA: standard.2009.06.24

And the seller, Jerry Dodge, was a hard-luck ne'er-do-well with a criminal record and what his friends and family describe as limited intellect and diminishing prospects.

NPR: Neighbor Sours On Property Sale To Vt. Governor

Democrats supported the bill with the exception of three Senators: Mary Landrieu (D-LA), Ben Nelson (D-NE) and Mark Begich (D-AL).

FORBES: Big Oil Tax Breaks Continue After Procedural Vote

Short and compact, on the Concept E-go, urban traffic will seem like a videogame that will be fun and easy to skilfully nE-gotiate.

ENGADGET: BMW unveils concept Husqvarna Concept E-go electric motorcycle