Suffixes may be attached to nouns, adjectives or adverbs.  The final vowel of the word should be dropped before adding the suffixes.  The endings -ino, -ina, -ello, -ella, -etta, -etta, -uccio, and -uccia are diminutives that express smallness.  The endings -one and -ona are augmentatives and express largeness.  The endings -ino and -uccio also express endearment.  The endings -aacio, -accia, -astro, -astra, -azzo, and -azza imply ugliness or poor quality.

Tesorino mio!  My sweetheart!
Amoruccio mio!  My sweet love!

Most adverbs are formed by adding -mente to the feminine singular form of the adjective.  Adjectives ending in -le or -re drop the final -e before adding -mente, if the l or r is preceded by a vowel.

Note that the adverbial form of buono (good) is bene, and cattivo (bad) is male.

In passive sentences, the subject receives the action of the verb.  In active sentences, the subject does the action.  However, the meaning of both sentences is the same.  The passive form is only possible with transitive verbs and is much more common in English than in Italian.  The passive form consists of the verb essere plus the past participle of the main verb followed by da (by) and its contractions.  Essere should be in the same tense as the verb in its corresponding active sentence.  The past participle agrees in gender and number with the subject.

I contratti sono firmati dalle ragazze.  The contracts are signed by the girls.
La stanza è stata arredata da Carlo.  The room was decorated by Carlo.
L'affito sarà pagato dai miei genitori.  The rent will be payed by my parents.

Si can be used as a reflexive pronoun, but it can also be used as an impersonal pronoun.  It corresponds to "one, you, we, the people in general, or they" in English and always use the third peron form of the verb (either singular or plural depending on the object).

Qui si vende carta da lettere.  We sell writing paper here./Writing paper is sold here.
Si vendono anche matite?  Do you also sell pencils?
Qui non si parla francese.  We don't speak French here./French is not spoken here.