In Italian, some prepositions combine with definite articles to form a single word. These combinations are called articulated prepositions (preposizioni articolate). They are very common in everyday Italian and are used to express relationships such as possession, location, movement, and origin. For example, the simple preposition a means to or at, but when it is followed by the definite article il, the two words combine to form al. Similarly, di + la becomes della, and in + il becomes nel.
Articulated prepositions are formed with five simple prepositions: di, a, da, in, and su. The form depends on the definite article that follows the preposition. Since Italian articles change according to gender, number, and the beginning of the noun, articulated prepositions change in the same way. The other simple prepositions, per, tra, and fra, remain separate from articles. The preposition con also normally remains separate in everyday Italian.
How Articulated Prepositions Work
The basic rule is simple: when one of the five prepositions is followed by a definite article, the two normally combine into a single word. The article keeps the same form it would have without the preposition, but becomes part of the new word. For example, il libro becomes del libro after di, al libro after a, and sul libro after su. With feminine nouns, la casa becomes della casa, alla casa, or sulla casa. The same principle applies to plural nouns and to articles such as lo, gli, and le.
The choice of articulated preposition therefore depends on two things: the meaning of the simple preposition and the correct definite article for the noun. First, choose the preposition that expresses the relationship you need. If the expression also requires a definite article, combine the two. For example, if you want to say in the garden, Italian uses in for location and il for giardino, producing nel giardino. If you want to say of the students, Italian uses di and gli, producing degli studenti. You do not need to learn a new meaning for every combined form: the meaning comes from the original preposition, while the ending reflects the article.
Il libro del professore è interessante. — The teacher's book is interesting.
Vado al mercato. — I'm going to the market.
Sono nella mia camera. — I'm in my room.
Il gatto è sul divano. — The cat is on the couch.
Parlo agli studenti. — I'm speaking to the students.
The prepositions di, a, da, in, and su keep their basic meanings when combined with articles. Di commonly expresses possession or a relationship between nouns, a indicates a destination or location, da often means from, in indicates location, and su means on. Articulated prepositions are used when an expression requires a preposition followed by a definite article. However, not every expression needs an article. For example, Italian normally says a Roma (in Rome), in Italia (in Italy), and di Marco (Marco's), without an article. These expressions therefore use simple prepositions rather than articulated ones.
A particularly important detail concerns words beginning with a vowel. The forms dell', all', dall', nell', and sull' are used before nouns that require the article l'. With masculine nouns beginning with certain consonant combinations, such as st in studente, Italian uses forms based on lo or gli rather than il or i. This produces combinations such as dello studente and agli studenti. These forms follow the same rules as definite articles.
Vado all'università. — I'm going to the university.
La macchina dell'amica è nuova. — The friend's car is new.
Il libro dello studente è sul tavolo. — The student's book is on the table.
Summary of Articulated Prepositions
The following table shows all the regular combinations of the five prepositions with the seven forms of the definite article.
| Preposition | il | lo | la | l' | i | gli | le |
| di | del | dello | della | dell' | dei | degli | delle |
| a | al | allo | alla | all' | ai | agli | alle |
| da | dal | dallo | dalla | dall' | dai | dagli | dalle |
| in | nel | nello | nella | nell' | nei | negli | nelle |
| su | sul | sullo | sulla | sull' | sui | sugli | sulle |