The so-called Sumerian conjugation prefixes are the most poorly understood and perplexing elements of Sumerian verbal morphology. Approaching the problem from a functional-typological perspective and basing the analysis upon semantics, Professor Woods argues that these elements, in their primary function, constitute a system of grammatical voice, in which the active voice is set against the middle voice. The latter is represented by heavy and light markers that differ with respect to focus and emphasis. As a system of grammatical voice, the conjugation prefixes provided Sumerian speakers with a linguistic means of altering the perspective from which events may be viewed, giving speakers a series of options for better approximating in language the infinitely graded spectrum of human conceptualization and experience.