Learn French: Notre chef est d'accord, à moins que le vôtre ne soit contre. - Our boss agrees, unless yours is against it.

The conjunction à moins que (unless) expresses a condition or a reservation, which introduces a level of uncertainty or subjectivity. In French, this requires the following verb to be in the subjunctive mood. Soit is the third-person singular subjunctive of être (to be).

What is the ne doing before soit? Does it make the sentence negative?

No, it's not a negative! This is called the ne explétif (expletive ne). It is often used after certain conjunctions like à moins que and avant que, as well as after verbs of fearing. It doesn't change the meaning of the sentence and is not translated into English. It is mostly a stylistic choice that makes your French sound more elegant and authentic, especially in written form.

Why does vôtre have a circumflex accent (^) when Notre at the beginning of the sentence doesn't?

Notre is a possessive adjective (meaning "our") and goes directly in front of a noun (notre chef). On the other hand, le vôtre is a possessive pronoun (meaning "yours") that replaces a noun to avoid repetition. In French, the possessive pronouns (le nôtre, la nôtre, le vôtre, la vôtre) always have a circumflex to distinguish them in spelling and pronunciation from the adjectives (notre, votre).

How come there is no word for "it" in soit contre (is against it)?