It is well known that, in languages of the world, the passive expression is related to constructions such as reflexives and reciprocals. This paper pays special attention to the less familiar correlations of passives to spontaneous, potential, honorific, and plural formations; and it is argued that presently available characterizations of the passive are unable to offer explanations for these correlations. A satisfactory characterization must include a framework in which one can determine the nature of 'pseudo-passives', 'impersonal passives' etc. To achieve these goals, a prototype approach is adopted, and the passive prototype is defined. It is also shown that current controversies over whether passives should be analysed as promotional or demotional phenomena find a natural answer when a wider range of passive-related phenomena is examined.