Rule reminder
Summary: (1) Form: feminine + -mente; drop -e for -le/-re adjectives. (2) Irregular: bene, male, meglio, peggio. (3) Position: after verb. (4) Intensifiers: molto, troppo, abbastanza, poco, davvero, proprio — always invariable. (5) Adverb vs adjective: adverbs are invariable.
Quale avverbio si forma da 'difficile'? (Which adverb is formed from 'difficile'?)