We use modal verbs to express a necessity, a possibility or a volition (if you must do something, if we can do something or if we want to do something).

We also use modal verbs to do things like asking permission, making requests and offers and so forth.

The Italian modal verbs always precede the infinitive of another verb and indicate a mode

  • voglio andare al supermercato (modal verb + infinitve + object)
  • devo comprare la cioccolata (modal verb + infinitve + object)
  • non posso aspettare (modal verb + infinitive )

What do they mean in English?

DOVERE

Dovere + infinitive: to must, to have to, I need to 

  • Devo andare in palestraI must (need, have to) go to the gym

Dovere + object: to owe 

  • Ti devo 5 euro per la piazza – I owe you 5 euros for the pizza
POTERE

Potere: to ask for permission or being allowed (or not allowed) to do something

  • Posso uscire un momento? – Can I leave for a second?
  • I bambini non posso guardare la tv di sera tardi – Children are not allowed to watch TV late

Potere does not express the ability to do something, like English. In Italian, is always the verb SAPERE that does it:

  • so cantare – I can sing
  • sai cucinare? –  Can you cook?
  • sapete parlare russo? – Can you guys speak Russian?
VOLERE

Volere: to want

  • Voglio mangiare giapponese – I want  to eat Japanese
  • Voglio il shushi e la tempura – I want sushi and tempura

 

Modal verb and compound tenses

Conjugating modal verbs in the passato prossimo (and other compound tenses) needs a special construction.

Since each modal verbs is followed by an infinitive verb (Posso entrare? Voglio mangiare!), when it comes to conjugating the modal verb you always need to choose the correct auxiliary (essere or avere)  of the infinitive verb following the modal verbs:

  • Sono dovuta uscire  – I had to leave

Uscire is a verb of motion that in compound tenses take essere as a helping verb (or auxiliary), for such reason the auxiliary of dovere is essere, in such case. 

  • Ho dovuto preparare la cena – I had to prepare the dinner

Preparare is a transitive verb taking avere as helping verb, for such reason the auxiliary of dovere is avere, in such case.

  • Non ho potuto preparare la cena – I could not prepare the dinner
  • Non sono potuta andare a pranzo – I could not go to the lunch

Note that if the auxiliary preceding the modal verb is essere, the modal verbs dovere, potere and volere agree with the gender and number of the subject.

  • sono dovuta andare via – I had to leave 
  • ci siamo alzati tardi – we got up late 
  • non siamo potuti venire – we could not come