An article is a word that modifies a noun in a particular way, by stating whether the noun is specific, unspecific, or partial. There are three types of Italian articles, and they all agree in gender and number with the nouns they modify. A1 - Beginning Italian • agreement
Articulated prepositions are the contractions of certain Italian prepositions with definite articles. In English, contractions like "I’m" and "won’t" are optional and indicate informality. In Italian, however, preposizioni articolate are required, regardless of the register you’re speaking or writing in. 
In Italian, consonants can be divided into pure and impure sounds (or simple and complex sounds). While both types can occur anywhere in a word, they only really matter, grammatically speaking, at the beginning of masculine nouns. 
The Italian definite article (il, lo, la, i, gli, le) indicates either a particular noun or, contrarily, the general sense of a noun. A1 - Beginning Italian • agreement • gender • plurals
The aptly named indefinite article (un, uno, una, dei, degli, delle) indicates an unspecific or unidentified noun. A1 - Beginning Italian • agreement • gender • indefinition • plurals
The partitive article (del, dello, della, dei, degli, delle) refers to an unspecified quantity of food, liquid, or some other uncountable noun. English has no equivalent article – the partitive is usually translated by the adjectives “some” or “any,” or may be left out entirely. A1 - Beginning Italian • agreement • gender • plurals
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. 