Expressions of agency in ancient Greek is a meticulous study of the development of passive-with-agent constructions (PACs) in ancient Greek, covering the timespan from Preclassical Greek to the 12th century ce. The author focuses on the complex history of the various, primarily prepositional, agent markers of passive voice verbs in various moods and tenses, such as participles or perfect verbs. He defines a passive verb as a detransitivized verb that retains the idea of agency whether or not it is expressed. The agent is to be defined as an oblique nominal occurring with a passive verb that would be the subject if the sentence were rewritten in the active voice.

Comparing this work with others on the same subject in the early and recent bibliography, on the basis at least of the book's internal evidence, no similar treatment of agency in ancient Greek has been made or attempted in terms of its completeness. The author draws comparisons with other languages and traces central themes such as the passive voice back to Proto-Indo-European and to other classical languages such as Sanskrit or Latin. An important feature of this book is that C. H. George has traced similarities in the expression of agency between ancient Greek and the Mayan language K'iche.

Some of the major analytical tools used by George in this treatise are an animacy hierarchy referring most directly to the relations between the agent and its patient; the role of the verb in selecting the proper preposition as an agent marker – for example, whether or not we are dealing with morphological or suppletive variants of the verb; and most crucially, the particular verb semantics classified on a semantic cline (verbs of sending, telling, etc.). Such analytical concepts are applied to a vast and thoroughly examined collection of extracts ranging from Homeric Greek to Classical prose and poetry (tragedy, comedy) to later periods, including the Septuagint, the New Testament, and much later texts such as the epic of Digenis Akritis. In all these, both the simultaneous use and the replacement over time of one preposition by another become central foci of the book's core.

Had the author included some information on social and cultural parameters, the book would be quite relevant to a sociolinguist's interests. However, this by no means suggests that pragmatic factors such as, for example, the role of PACs in the expression of narrative theme and others are not discussed in the text. Agency is a very broad issue in the study of languages and linguistics that almost resembles a total linguistic fact, in a spirit similar to how anthropologists view the concept of the “Gift” – that is, as a total social fact. Important aspects of this totality, the morphosyntactic and semantic evolution of PACs in ancient Greek, are carefully treated in this book. Expressions of agency in ancient Greek is addressed to language typologists, historical linguists, comparativists, and primarily classicists.