Breakdown of Nous ajoutons la vanille avant que la tarte cuise.
nous
we / us (object pronoun)
ajouter
to add
la vanille
the vanilla
avant que
before (conjunction)
Questions & Answers about Nous ajoutons la vanille avant que la tarte cuise.
Why is the verb "cuise" used here instead of the regular present tense "cuit"?
Because of the phrase avant que (before). This conjunction always requires the verb that follows it to be in the subjunctive mood. cuise is the third-person singular subjunctive form of cuire (to cook/bake).
If "cuire" means "to cook", how do we know it means "to bake" in this sentence?
Could we use "avant de" instead of "avant que" to make it simpler?
Not in this sentence! You only use avant de followed by an infinitive verb when the subject is the exact same for both actions. Here, "we" (nous) add the vanilla, but "the tart" (la tarte) is doing the baking. Because the subjects are different, you must use avant que followed by the subjunctive.
I sometimes see a "ne" after "avant que", like "avant que la tarte ne cuise". Is that required?
That is called the "ne explétif" (expletive ne). It is completely optional and doesn't change the meaning or make the sentence negative. It just makes the French sound a bit more formal and elegant in writing. In everyday speech, it is very common to leave it out, just like in our example.