Can, be able to
Potere
I can
Posso
You can
Puoi
He/she/it can
Puo
We can
Possiamo
(Plural) you can
Potete
They can
Possano (po-sa-no)
I could
Potrai
You could
Potresti
He/she/it could
Lui/lei poteva
We could
Not potevamo
Plural you could
Voi potevate
They could
Loro potevano
I could have
Ho potuto
You could have
Tu potuto
He/she/it could have
Lui/lei potuto
We could have
Nio potuto
Plural you could have
Voi potuto
They could have
Lori potuto
I could
Potrei
You could
Potresti
She could
Potrebbe
We could
Potremmo
Plural you could
Potreste