Si is a special pronoun used when the subject is general, indefinite, or unspecified. It often corresponds to the English one, people, you, or they in general statements. Understanding how to use si properly will not only improve your comprehension but also make your speech sound more natural and fluent.
The pronoun si makes the sentence impersonal, referring to people in general, or the subject is general and unspecified; no particular person is doing the action.
Chiara parla italiano.
Chiara speaks Italian. – A specific person is doing the action.
In Italia si parla italiano.
In Italy, they speak Italian.
The verb following si is generally conjugated in the third person singular, except in some plural cases (see below).
In questo ristorante si mangia molto bene.
One eats very well in this restaurant.
Si vive una volta sola.
You only live once.
Con l’autobus si può arrivare in centro in dieci minuti.
You can get to the city center in ten minutes by bus.
Non si sa chi sia il responsabile.
It is not known who is responsible.
Si parla molto di questa questione.
There’s a lot of talk about this issue.
To make a sentence negative, place non before si:
Non si mette l’ananas sulla pizza.
You don’t put pineapple on pizza.
Non si può fumare qui.
Smoking is not allowed here.
When using si with essere, and the noun is plural, the verb is plural as well:
Quando si è giovani, si fanno cose stupide.
When one is young, one does foolish things.
Si è sempre pronti a dare la colpa agli altri.
One is always ready to blame others.
With the past tense, si uses essere as an auxiliary verb. The past participle agrees in gender and number.
Non si è potuto fare nulla.
Nothing could be done.
Si è parlato molto di questo argomento.
There has been much talk about this topic.
Si è fatto molto per le vittime del terremoto.
Much has been done for the earthquake victims.
When the impersonal si is used with a reflexive verb, the impersonal si becomes ci to avoid repetition:
Non ci si parla da giorni.
We haven’t talked for days.
Ci si impiega un’ora ad arrivare a Roma.
It takes an hour to get to Rome.
Ci si diverte molto in questa città.
One has a lot of fun in this city.
In questa palestra ci si può allenare tutti i giorni.
In this gym, one can work out every day.
