This study set out to help one secondary school, science teacher on the use of questioning for formative assessment in the class. During the data collection period, I worked very closely with him, working in a community school, to introduce the use of questioning for formative assessment in chemistry in class eight. I collected data for this study over a period of seven weeks. I gathered the data through classroom observation, unstructured interviews and informal discussions. I also kept a journal throughout the period of data collection where I noted important points, my feelings, and new questions that emerged concerning questioning for formative assessment. I reflected deeply on my role as a teacher educator, change agent, and learner. The dissertation contains thick descriptions of planning, teaching and post teaching interactions that highlight the delicate relationship the researcher had with the research participant. Findings of the study show improvement in questioning skills for formative assessment of my research participant. He improved on question distribution, seeking opinions from other students, probing, sharing learning intentions with his students at the beginning of the sessions and providing feedback to the students. Also, the findings show numerous possible challenges that a teacher might face during the use of questioning for formative assessment. The challenges were time, the number of students in the classroom, a noisy class, the problem of students cramming (rote memorization), and practical knowledge of the teacher. Likewise, the researcher faced a number of challenges that ranged from a lack of expertise in co-planning, co-teaching and lack of competence for conducting action research.