The elusive but revealing preposition "di"

or "complemento di specificazione"

If we examine three chunks like

1) La Fiera di Milano

2) Il libro di Giovanni

3) Vestito di grigio

we note the presence of the preposition "di" introducing a prepositional phrase traditionally labelled “complemento di specificazione.” The first instance, however, is an expression of place (a locative, if you like technical terms):

1a) The Trade Fair that takes place in Milan;

the second is an example of possessive case:

2a) The book that belongs to John (certainly NOT *The book that takes place in John); See

in less frequent cases, “di Giovanni” may mean "about John", if Giovanni is the topic of the book; or, finally, “di Giovanni” may mean "by John" if he is the author.

An analysis of the third example is more complex and if “complemento di specificazione” is too generic, we can label it as “complemento di abbigliamento” (something like "adverbial of dress") — which shows that such labels are arbitrary and not always useful.

Other phrases with "di" are related to notions of time,

4) Viaggiare di sabato

subject or topic,

5) Parlare di grammatica

6) Discutere di politica

or cause

7) Tremare di paura;

then there are comparisons,

8) Meglio di ieri

"di" before an infinitive,

9) Sono lieto di saperlo

the use of "articled forms" in partitives

10) Dammi del pane

and several more cases, including:

11) Coperto di neve

12) Una commedia di G.B. Shaw.

Comparative analyses are the most immediate test to highlight differences; the Eng. translation of the examples gives

1’) The Milan Trade Fair

where the location becomes a premodifier;

2’) John’s book

where the owner takes the mark of the possessive case;

3’) Dressed in grey

4’) Travelling on Saturday(s)

5’) Talking about grammar

6’) Discussing politics

7’) To tremble with fear

8’) Better than yesterday

9’) I’m glad to hear that

10’) Give me some bread

11’) Covered with snow

12’) A play by G.B. Shaw

where we find that It. "di" is translated with the Eng. prepositions "in, on, about, with, by" the conjunction "than", the partitive "some", "to" before an infinitive and even ø (zero) as in (6’). A lot more examples could be added, including those where It. "di" corresponds to Eng. "of" and are regarded as following the “general rule”:

13) La metà di giugno

13’) The middle of June

In short, "doing grammar" always implies that meanings are taken into account.

As a consequence the often has a crucial role: in some cases

2’b) The book of John

is understood to mean

2’c) The Gospel according to John.