Learn French: Tout ce qui est recyclable doit être apporté à la déchetterie. - Everything that is recyclable must be brought to the recycling center.

To form the passive voice with a modal verb, you conjugate the modal verb (here, doit from devoir) and follow it with the infinitive être and the past participle of the main verb (apporté). Just like in English, the modal verb expresses the obligation, while the passive construction shows that the subject receives the action.

Does the past participle apporté need to agree with the subject in this passive construction?

Yes. In any passive construction with être, the past participle must agree in gender and number with the subject. Here, the subject is Tout ce qui (Everything that), which is treated as masculine singular, so apporté remains in its default masculine singular form. If the subject were feminine, like La boîte (The box), it would be doit être apportée.

Why do we use ce qui instead of ce que after Tout?

We use ce qui because it acts as the subject of the verb in the relative clause (est recyclable). If the pronoun were the object of the verb, you would use ce que, as in Tout ce que je vois (Everything that I see). A helpful rule of thumb: qui is usually followed directly by a verb, while que is followed by a new subject.

What is the difference between a and a regular dump?