o = or oppure = or, or else, otherwise ovvero = or, or else (used less frequently than o or oppure); or rather; that is, in other words altrimenti = otherwise, or else
O
O is the equivalent of the English or, which usually proposes another option or idea in a sentence:
Ti piace di più passare le vacanze al mare o in montagna? Do you enjoy spending your vacation more at the beach or in the mountains?
It can also be used to express the “either.. or” construction in English: