Not all adjectives can be formed into adverbs; for example, the words postalmente and malatamente do not exist. On the other hand, not all Italian adverbs are formed from adjectives. When in doubt, check the dictionary.

ADVERBS THAT DON’T DERIVE FROM ADJECTIVES
 
ancora
 still
 
attorno
 around, about
 
bene
 well
 
contro
 against
 
dentro
 in, inside
 
dietro
 behind, at the back of
 
dopo
 then, afterwards
 
fuori
 outside
 
già
 already
 
inoltre
 moreover
 
insieme
 together
 
male
 badly
 
(non)...mai
 never
 
(non)...più
 no longer, not anymore
 
oltre
 beyond
 
presto
 soon, before long
 
sempre
 always
 
sopra
 above, on top
 
sotto
 underneath, below
 
vicino
 nearby, close by
 

Adverbs always precede the adjective or adverb that they modify, and they generally follow a simple verb form. For example: Beve sempre la birra. (He always drinks beer.) In sentences with compound tenses, most adverbs are placed after the past participle. For example: Sono arrivato tardi al museo. (I arrived late at the museum.) However, certain common adverbs such as già, ancora, sempre, (non)...mai, and (non)...più are inserted between the auxiliary verb and the past participle of the compound form:

Non ci sei più andata. (You don’t go there anymore.)

Enzo è sempre venuto in orario. (Enzo always came on time.)

Non ho ancora finito i miei compiti. (I still hadn’t finished my homework.)