Learn Italian: Le chiavi sono cadute dal tavolo.

In Italian, the passato prossimo (past tense) uses either avere or essere as a helper verb. Verbs that describe a motion or a change of state, like cadere (to fall), use essere. Since the subject le chiavi (the keys) corresponds to "they", we use sono.

Why is it cadute and not caduto?

Because we are using the helper verb essere, the past participle (caduto) has to agree with the subject, just like an adjective. The subject is le chiavi, which is feminine plural. So, caduto changes its ending to -e to become cadute.

Wait, chiavi ends in -i, so isn't it masculine plural?

No, it is actually feminine plural! The singular word is la chiave (the key). Nouns that end in -e in the singular change to -i in the plural, whether they are masculine or feminine. You can tell it is feminine here because of the feminine plural article Le and the matching ending on cadute.

Where does the word dal come from?