Italiano — Passivating si
The particle si turns an active verb into a passive-like construction: si vende casa means "a house is for sale". The verb agrees with the grammatical subject, so it becomes plural in si vendono case.
How it works
Use si + a transitive verb in the 3rd person; the object of the active sentence becomes the grammatical subject, and the verb agrees with it. Singular subject → singular verb (si vende casa); plural subject → plural verb (si vendono case). It expresses actions with no specified agent, like "one" or the passive voice.
Agreement in practice
| Sentence | Meaning |
|---|---|
| Si vende casa. | A house is for sale. (singular subject casa) |
| Si vendono case. | Houses are for sale. (plural subject case) |
| Qui si parla italiano. | Italian is spoken here. (singular subject italiano) |
| Si leggono molti libri. | Many books are read. (plural subject libri) |
| Non si accettano carte di credito. | Credit cards are not accepted. (plural subject carte) |
| Da qui si vede il mare. | The sea can be seen from here. (singular subject mare) |
Good to know
Do not confuse the si passivante with the impersonal si used with intransitive verbs, which stays singular: si mangia bene qui ("one eats well here"). With a transitive verb and a plural object the verb must be plural: say si vendono case, not si vende case.