Il si impersonale

The “si” impersonale (impersonal “si”) is used when describing what people usually do or how things are usually done. In English, the best equivalents are “one,” “you,” or “people” to speak generally. This form is also referred to as “si” passivante (passive “si”) as it allows one to form passive sentences without one active subject.

Come si usa questa forma?

This form can be used only with a verb conjugated in the third person singular or plural (lui/lei/loro).

The verb is conjugated based on whether the object of the verb is singular or plural.

• Singular object: si + 3rd singular (lui/lei)
  • Si compra un biglietto per il treno.
• Plural object: si + 3rd plural (loro)
  • Si vedono molti passeggeri sul binario

Nota importante:

• When there’s no object OR a preposition following the verb, we must use si + 3rd singular:
  • In Italia, si paga con i contanti o con la carta di credito?
  • Si viaggia in traghetto per arrivare ad Olbia, in Sardegna.

Verbi riflessivi

• Reflexive verbs (mettersi, vestirsi, etc.) work beautifully in an impersonal construction, but they still require their reflexive pronoun. So, you will have double pronouns in a reflexive impersonal construction.
• To avoid repeating “si” twice in a row, change the first “si” to “ci.”
  • People wear sunscreen at the beach.
  •  si si mette -> ci si mette
  • Ci si mette la crema solare in spiaggia.

Verbi modali

• Modal verbs (potere/dovere/volere) followed by a transitive infinitive must agree with the object of the infinitive. (I.e., think about what comes after the main verb)
  • Si possono comprare i biglietti in anticipo.
  • Si può fare colazione
• Modal verbs followed by an intransitive infinitive take the singular form. (If it helps, you can consider this an extension of the above “nota importante”).
  • Si deve partecipare al Rome Study Program per vivere un’esperienza indimenticabile!
  • Si può viaggiare a molte città italiane con un treno diretto da Roma Termini.