Purpose: This study explores prospective classroom teacher (PCT) question types and their role in initiating productive student-led talk. Design/Approach/Methods: This study is a naturalistic inquiry focusing on the structure, nature, and productivity of PCT questions using data collected from 24 fourth-grade (exit-level) PCTs. Video-based data were analyzed via systematic observation. Findings: This study identified nine types of teacher questions. Of these, six types--namely, communicating, monitoring-framing, critiquing, legitimating, evidencing, and modeling--were explicitly related to productive classroom talk indicators. While the remaining three question types--observe-compare-predict, concluding and naming, and maintaining--contributed to the variation in PCT questions, they were not directly linked to the indicators of talk productivity. Moreover, the critiquing, legitimating, and modeling questions expected to foster talk productivity were seldom asked, with classroom discourse dominated by communicating questions. Originality/Value: The literature has yet to observe and systematically analyze the productivity of PCTs' in-class questions. In addressing this gap, this study presents a wide-ranging and qualitatively oriented coding catalogue to identify several aspects of academically productive classroom discourse that can be triggered and maintained by PCTs' questioning behaviors.