Grammar is associated with discourse. In other words, grammatical phenomenon requires an explanation at the level of discourse. This is related to pragmatical appropriateness, which is hard to explain at the level of sentence and becomes a foundation to provide an explanation of when specific grammar is used and why specific grammar is used in that context. Thus, this study aimed to examine discourse conditions for proper passive use by analyzing discourse functions of passives in spoken discourse. The discussions are as follows. First, passives are used when agents are not important contextually and uncertain, or they don`t exist. This results from the information structural characteristic of passives that man who is suffered acts is placed in a topic`s position. Second, passives are used to maintain a topic that is a center of discourse. This is related to cohesion and coherence of discourse and comes from the information structural characteristic of passives too. Third, passives are used in politeness and relieving burdens among interpersonal functions, since the semantic characteristic of passives for positivity removal makes it to express indirectly.