Sicilian is estimated to have millions of speakers. However, it remains very much a home language spoken among peers and close associates. The regional Italian dialect has encroached on Sicilian, most evidently in the speech of the young generations.
It should be taken as a given that Sicilian is an independent language in its own right. It is not a dialect of Italian. Some assert that Sicilian represents the oldest Romance language derived from Vulgar Latin, but this is not a widely-held view amongst philologists.
The language has inherited vocabulary and/or grammatical forms from all of the following: Greek, Latin, Arabic, French, Lombard, Provençal, German, Catalan, Spanish and of course Italian, not to mention prehistoric influences from the earliest settlers on the island. The very earliest influences, visible in Sicilian to this day, exhibit both prehistoric Mediterranean elements and prehistoric Indo-European elements, and occasionally a cross-over of both.
Before the Roman conquest, Sicily was occupied by remnants of the autochthonic populations (Sicani, Elymi, Siculi, (the latter arriving between the second and first millennium BC), as well as by Phoenicians (from between the 10th and 8th centuries BC) and Greeks (from the 8th century BC). The Greek influence remains strongly visible, however, the influences from the other groups are less obvious. What can be stated with certainty is that there remain pre-Indo-European words in Sicilian of an ancient Mediterranean origin, but one cannot be more precise than that. Of the three main prehistoric groups, only the Siculi were Indo-European, and their speech is likely to have been closely related to that of the Romans.
Poets in Sicily sometimes write in Sicilian. However, most speakers (especially the youngest ones) are literate just in Italian, not Sicilian; this implies a poor knowledge of the written language in all its grammar and spelling rules, in contrast to a still wide diffusion of spoken Sicilian in the island.
The education system does not support the language. Local universities do not carry courses in Sicilian, or where they do it is described as dialettologia, that is, the study of dialects.
As one of the most-spoken languages of Italy, Sicilian has notably influenced the Italian lexicon. In fact, there are several Sicilian words that are nowadays part of the Italian language; they usually refer to things closely associated to Sicilian culture, with some notable exceptions.