One of the eight parts of speech, adjectives are a type of modifier; that is, they modify or describe nouns in a certain way, letting you know the size, shape, weight, color, nationality, or any of a myriad other possible qualities of nouns.
Adverbs of manner express how the action of a verb occurs. In English, the vast majority of adverbs of manner end in -ly, whereas in Italian, they mostly end in -mente. They are usually created from adjectives.
Italian possessive adjectives are used in front of nouns to indicate to whom or to what those nouns belong. They are considerably more complicated than English possessive adjectives because Italian has many different forms depending on the gender and number of the possessed noun.