In this dissertation, I investigated the usage of subordinators in Ancient Greek dialectal inscriptions and their interactions with supradialectal formulas, i.e., relatively fixed expressions shared across dialectal borders. Subordinators are grammatical elements and therefore are expected to behave in a systematic manner; supradialectal formulas are expected to provide a "test tube", revealing how different dialects express the same notion. As the first step, I compiled an up-to-date collection of known attestations of subordinators in the dialects of Mainland Greece. Using this collection, I investigated the interactions of local dialects and the standard language in the contexts of fixed expressions and creative composition. In some cases, the confinement of a subordinator into a fixed expression suggests its inactive status in the dialect, and in contrast, the active status of a subordinator is illustrated by its appearances in supradialectal formulas replacing non-local subordinators. Uses of non-local subordinators often result from the predominance of the standard language, but sometimes from the borrowing of phraseological units as a whole rather than the borrowing of the subordinator alone. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]