“J'ai peur que vous ne deviez y aller en personne” vs “J'ai peur que vous deviez y aller en personne.” [duplicate]

Question

I've come across with the following sentence:

J'ai peur que vous ne deviez y aller en personne.

I thought it meant something like "I'm afraid you shouldn't go there in person" because of the adverb "ne". However, it doesn't actually negate the sentence. Here are Google Translate outputs with and without "ne":

• with: "I'm afraid you might have to go there in person."
• without: "I'm afraid you have to go there in person."

Can someone explain why this happens and if there's grammar term for it or something like that?

Answer 1

In grammar, this ne is called an expletive, i.e. a word "used without being needed for the meaning or syntax of a sentence."

Here are some explanations:

The ne explétif does not add any meaning – negative or otherwise – to the sentence; it’s just there to draw attention to what precedes it. It’s formal and optional, and used after certain verbs and expressions that have a negative meaning, in either sense of the word: negative as in bad (fear, warning) or negative as in negated (denial, doubt). The most important thing to remember is that the ne explétif does not negate the verb it precedes; for that, you need pas.

If you need additional documentation, look at here.

Answer 2

To add to grouah's answer, this ne is probably a reflection of the same particle found in Latin, as Grevisse points out (Bon usage, 14th ed. §1023 H1). That particle was to be found before the object clause of verbs expressing worry or fear, which is also the most common occurrence in French (In Latin, said object clause could even be negative in its own right). Its usage is expanded to various other construction now.