There are few sources concerning the language in the dark ages, a time of turmoil, barbarian incursions and population movements. This period, however, appears to have played a decisive part in the formation of the Modern Greek dialects. For instance, during this period the short forms of several words that are used to this day were formed by dropping the initial and final unstressed vowels, as in 'ospition' > 'spiti' (house), 'opsarion' > 'psari' (fish), 'eroto' > 'roto' (ask) etc.
In this period the spoken language continued to acquire loan-words from other tongues: mainly from Latin, as in Late Antiquity, and possibly from Slavonic as well, since Slav-speaking populations started settling in Macedonia (although the majority of the population remained Greek-speaking). Compounding was another source of new vocabulary that was greatly used in this period, as in 'toxofaretron' (bow and quiver), 'eisoexodos' (entry and exit), 'asproforeo' (to wear white) etc.