Aeolian has some archaic traits kept from Common Hellenic. The Homeros's epic was written in the language very close to Aeolian.
The language has the following basic peculiarities:
a) the so-called "psylosis" - no strong aspiration which was derived in Greek from Proto-Indo-European initial *s- and other sounds;
b) the Common Greek long á was preserved (e.g. ádu, Attic hédu)
c) labiovelar consonants turned into labials before e, i (e.g. pempe - five, Ionian pente)
d) the syllable r from Proto-Indo-European became here or / ro (e.g. strotos - an army, Attic stratos)
e) the assimilation of sonore consonants in sm, sn, sl combinations (e.g. emmi - I am, Attic eimi < esmi)
f) no dual number (coincided with plural)
g) the verbs ending in -eó turned to athematic -mi declension (e.g. kalémi, Attic kaleó)