This study is concerned with the description, or, the basis of recordings of informal conversations between young educated AtInenian peers, of the interrelated patterns of variability and invariance obtaining in the verb inflection in Modern Greek Koine. The analysis is conducted within the variationist generative framework, i.e. it is committed to exhaustiveness and explicitness, but unlike the traditional (Chomksyan) generative model, it is based not only on the intuitions of the author but, more importantly, on observations of language in actual use. Variation phenomena are accounted for on the basis of the concept of variable rule. Use is also made of the insights gained by scholars working with-implicational scales. A central concern in the study is to avoid the identification of structuredness with invariance, characteristic of traditional generative theory, but also the all too common practice in much variationist literature of concentrating on a few (mostly phonological) variables that yield rich observed frequencies. Rather, we take the view that speakers make use both of invariance and of variability in their speech and that in the latter case differences in scores are not necessarily meaningful. Furthermore, speakers often engage, for the sake of stylistic effect, in the breaking of rules, a process resulting in episodic, yet highly meaningful, forms. The study is also concerned with accounting in explicit ways for variation phenomena sometimes related in the literature to the (unsatisfactory) concept of diglossia. Alternative analyses of the Greek verb inflection are examined and a number of structural places where inflectional formatives alternate are recognized. To account for all the acceptable "categorical" and "optional" combinations of inflectional formatives, a system of rules is set up. Furthermore, features of the linguistic and situational context are correlated with the probability of appearance of a number of variants in the output of a particular variable rule.