Describing how - or "complemento di modo"

The suffix "-mente" largely corresponds to Eng. "-ly" in deriving adverbs of manner from adjectives: "facilmente, grandemente, dolcemente"... ( easily, greatly, sweetly...)

For the rest, we find a variety of prepositions before adverbials of manner: "a caso, di fretta, con calma, per iscritto, in amicizia"... ( randomly, hurriedly, slowly/calmly, in writing, in a friendly way...)