Learn Italian: Ogni attrezzo si deve rimettere al suo posto. - Every piece of equipment must be put back in its place.

In this sentence, si deve rimettere translates to "must be put back". The passive "si" (si) is placed before the conjugated modal verb (deve), which is then followed by the main verb in its dictionary form, the infinitive (rimettere).

Can I attach the si to the end of the infinitive instead of putting it before deve?

Yes! With modal verbs like dovere (must), potere (can), and volere (want), you have two choices for where to put the pronoun. You can say si deve rimettere (before the conjugated verb) or deve rimettersi (attached to the dropped -e of the infinitive). Both mean exactly the same thing.

Why is the verb conjugated as singular (deve) when we are talking about putting away all the tools?

In a si passivante construction, the object being acted upon actually becomes the grammatical subject of the sentence. Because Ogni attrezzo (Every tool) is grammatically singular, the modal verb must be the singular deve. If the sentence were about plural tools, it would be Gli attrezzi si devono rimettere.

Could I use Tutti instead of Ogni to say "every piece of equipment"?