Ilirs are the descendants of Pelasgs. Albanians are the descendants of Ilirs.
Arguments for the Illyrian origin
The national name Albania is derived from Albanoi, an Illyrian tribe mentioned by Ptolemy about 150 AD.
From what is known from the old Balkan populations territories (Greeks, Illyrians, Thracians, Dacians), the Albanian language is spoken in the same region where Illyrian was spoken in ancient times.
There is no evidence of any major migration into Albanian territory since the records of Illyrian occupation.
Many of what remain as attested words to Illyrian have an Albanian explanation and also a number of Illyrian lexical items (toponyms, hydronyms, oronyms, anthroponyms, etc.) have been linked to Albanian.
Words borrowed from Greek (e.g. Gk (NW) "device, instrument" mākhaná > *mokër "millstone" Gk (NW) drápanon > *drapër "sickle" etc.) date back before the Christian era[50] and are mostly of the Doric Greek dialect, which means that the ancestors of the Albanians were in contact with the northwestern part of Ancient Greek civilization and probably borrowed words from Greek cities (Dyrrachium, Apollonia, etc.) in the Illyrian territory, colonies which belonged to the Doric division of Greek, or from contacts in the Epirus area.
Words borrowed from Latin (e.g. Latin aurum > ar "gold", gaudium > gaz "joy" etc.) date back before the Christian era,while the Illyrians on the territory of modern Albania were the first from the old Balkan populations to be conquered by Romans in 229–167 BC, the Thracians were conquered in 45 AD and the Dacians in 106 AD.
The ancient Illyrian place-names of the region have achieved their current form following Albanian phonetic rules e.g. Durrachion > Durrës (with the Albanian initial accent) Aulona > Vlonë~Vlorë (with rhotacism) Scodra > Shkodra etc.
The characteristics of the Albanian dialects Tosk and Geg in the treatment of the native and loanwords from other languages, have led to the conclusion that the dialectal split preceded the Slavic migration to the Balkans which means that in that period (5th to 6th century AD) Albanians were occupying pretty much the same area around Shkumbin riverwhich straddled the Jirecek line.
Arguments against Illyrian origin
The theory of an Illyrian origin of the Albanians is challenged on archaeological and linguistic grounds.
Although the Illyrian tribe of the Albanoi and the place Albanopolis could be located near Krujë, nothing proves a relation of this tribe to the Albanians, whose name appears for the first time in the 11th century in Byzantine sources
According to linguist Vladimir I. Georgiev, the theory of an Illyrian origin for the Albanians is weakened by a lack of any Albanian names before the 12th century and the relative absence of Greek influence that would surely be present if the Albanians inhabited their homeland continuously since ancient times. According to Georgiev if the Albanians originated near modern-day Albania, the number of Greek loanwords in the Albanian language should be higher.
According to Georgiev, although some Albanian toponyms descend from Illyrian, Illyrian toponyms from antiquity have not changed according to the usual phonetic laws applying to the evolution of Albanian. Furthermore, placenames can be a special case and the Albanian language more generally has not been proven to be of Illyrian stock.
Many linguists have tried to link Albanian with Illyrian, but without clear results. Albanian belongs to the satem group within Indo-European language tree, while there is a debate whether Illyrian was centum or satem. On the other hand, Dacian and Thracianseem to belong to satem. However, more recent research suggests that there was a process of satemization by which non-satem languages slowly acquired characteristics, and this characteristic has found parallels in the modern development of many Western European languages.[citation needed]
There is a lack of clear archaeological evidence for a continuous settlement of an Albanian-speaking population since Illyrian times. For example, while Albanians scholars maintain that the Komani-Kruja burial sites support the Illyrian-Albanian continuity theory, most scholars reject this and consider that the remains indicate a population of Romanized Illyrians who spoke a Romance language.