Ever since the fundamental studies carried out by the great German Romanist Max Leopold Wagner (b. 1880–d. 1962), the acknowledged founder of scientific research on Sardinian, the lexicon has been, and still is, one of the most investigated and best-known areas of the Sardinian language.
Several substrate components stand out in the Sardinian lexicon around a fundamental layer which has a clear Latin lexical background. The so-called Paleo-Sardinian layer is particularly intriguing. This is a conventional label for the linguistic varieties spoken in the prehistoric and protohistoric ages in Sardinia. Indeed, the relatively large amount of words (toponyms in particular) which can be traced back to this substrate clearly distinguishes the Sardinian lexicon within the panorama of the Romance languages. As for the other Pre-Latin substrata, the Phoenician-Punic presence mainly (although not exclusively) affected southern and western Sardinia, where we find the highest concentration of Phoenician-Punic loanwords.
On the other hand, recent studies have shown that the Latinization of Sardinia was more complex than once thought. In particular, the alleged archaic nature of some features of Sardinian has been questioned.
Moreover, research carried out in recent decades has underlined the importance of the Greek Byzantine superstrate, which has actually left far more evident lexical traces than previously thought. Finally, from the late Middle Ages onward, the contributions from the early Italian, Catalan, and Spanish superstrates, as well as from modern and contemporary Italian, have substantially reshaped the modern-day profile of the Sardinian lexicon. In these cases too, more recent research has shown a deeper impact of these components on the Sardinian lexicon, especially as regards the influence of Italian.