In Italian, when you want to make a generalization or talk about what “people” do, without saying who exactly, you use the impersonal form with si. It’s everywhere: on signs, in recipes, in conversation. In Italia si mangia bene. Let’s see how it works, step by step.
In short
- si + verb in the 3rd person singular: si mangia, si parte, si dorme.
- In English it’s “one,” “you,” “people,” “they” or a passive: Qui si parla italiano = Italian is spoken here.
- Si deve / si può = one must / one can: Non si può fumare.
- Bisogna + infinitive = it’s necessary: Bisogna prenotare.
- With reflexive verbs, si + si becomes ci si: ci si diverte.
- Adjectives after si are plural: Quando si è stanchi…
How to form the impersonal si
Si + verb in the third person singular. That’s it. The verb doesn’t change depending on who does the action, because nobody in particular does it.
| Italian | English |
|---|---|
| In Italia si mangia bene. | In Italy, people eat well. |
| In Italia si pranza tardi. | In Italy, people have lunch late. |
| Viaggiando si cresce. | You grow by traveling. |
| Come si dice “window” in italiano? | How do you say “window” in Italian? |
| Qui si sta bene. | It’s nice here. |
In English you translate it with one, you, people, they or with a passive. Choose what sounds most natural: Si dice che… = They say that… / It’s said that…
Si mangia or si mangiano? The si passivante
When the verb has a plural object, the verb goes into the plural. Grammar books call this the si passivante, but in practice it feels like the same structure:
| Singular object | Plural object |
|---|---|
| Si beve buon vino. | Si bevono vini buoni. |
| Si vende la casa. | Si vendono case. |
| Si parla italiano. | Si parlano molte lingue. |
More about it in my post on the passive voice.
Si deve, si può: the impersonal with dovere and potere
With dovere and potere, the impersonal form tells us what is necessary, allowed or forbidden. You’ll see it on signs all over Italy:
| Impersonal | Meaning |
|---|---|
| si deve + infinitive | one must, you have to |
| non si deve + infinitive | one must not, you shouldn’t |
| si può + infinitive | one can, you’re allowed to |
| non si può + infinitive | one can’t, you’re not allowed to |
At school… at the office…
| Italian | English |
|---|---|
| A scuola si deve studiare. | At school you have to study. |
| A scuola non si può usare il cellulare. | You can’t use your phone at school. |
| In ufficio si deve arrivare in orario. | At the office you have to arrive on time. |
| In ufficio non si può mangiare davanti al computer. | You can’t eat in front of the computer at the office. |
| Qui non si può fumare. | No smoking here. |
Bisogna: it’s necessary
Bisogna is an impersonal verb that means “it’s necessary.” It’s followed by an infinitive and it never changes. It’s a great alternative to si deve:
| Italian | English |
|---|---|
| Bisogna prenotare. | You need to book. |
| A scuola bisogna essere puntuali. | At school you have to be on time. |
| Al lavoro non bisogna fare tardi. | You shouldn’t be late for work. |
For more ways to say “need,” read dovere, servire and bisogno.
Ci si: the impersonal of reflexive verbs
Reflexive verbs already have a si in the third person: lui si diverte, lei si sveglia. To make them impersonal, we would need two si: si si diverte. That sounds terrible, so Italian replaces the first one with ci:
| Reflexive (he/she) | Impersonal (one/you) | English |
|---|---|---|
| si diverte | ci si diverte | one has fun |
| si sveglia | ci si sveglia | one wakes up |
| si rilassa | ci si rilassa | one relaxes |
| Italian | English |
|---|---|
| Viaggiando ci si diverte. | You have fun when you travel. |
| Nel weekend ci si sveglia tardi. | On the weekend you wake up late. |
| La domenica ci si rilassa. | On Sundays people relax. |
Not sure about reflexive verbs? Start with my guide to Italian reflexive verbs.
Si è stanchi: adjectives and the past
Two details that surprise many students:
- Adjectives and nouns after si are plural, even if the verb is singular: Quando si è giovani, si è felici con poco (When you’re young, you’re happy with little).
- In the passato prossimo, the impersonal si always takes essere: Ieri si è mangiato benissimo (We ate really well yesterday), Ci si è divertiti (Everyone had fun).
Exercise: complete with the impersonal form
- In Italia ______ (cenare) tardi.
- In questo negozio ______ (vendere) libri usati.
- In biblioteca non ______ (potere) parlare ad alta voce.
- In vacanza ______ (svegliarsi) tardi.
- ______ (bisognare) arrivare presto.
- Quando ______ (essere) stanchi, si lavora male.
Show the answers
- si cena
- si vendono
- si può
- ci si sveglia
- Bisogna
- si è
Frequently asked questions
How do you form the impersonal si in Italian?
Use si + the verb in the third person singular: si mangia, si parte, si dorme. In English it means “one,” “you,” “people” or a passive.
What is the difference between si mangia and si mangiano?
Si mangia is used with no object or a singular object (si mangia la pizza). With a plural object, the verb is plural: si mangiano le olive. This is called the si passivante.
What does “ci si” mean?
Ci si is the impersonal form of reflexive verbs: ci si diverte (one has fun), ci si sveglia (one wakes up). Italian uses ci instead of a double si.
What does “bisogna” mean?
Bisogna means “it’s necessary” and is followed by an infinitive: bisogna prenotare (you need to book). It never changes form.
Practice with my stories
Si mangia, si parte, ci si diverte: the impersonal form is everywhere in my stories, especially when characters discover how things work in Italy. Here are three to read next:
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Dive deeper: the passive voice · reflexive verbs · dovere, servire, bisogno
